WorldWideScience

Sample records for 2-d imaging diagnostics

  1. 2D-3D image registration in diagnostic and interventional X-Ray imaging

    NARCIS (Netherlands)

    Bom, I.M.J. van der

    2010-01-01

    Clinical procedures that are conventionally guided by 2D x-ray imaging, may benefit from the additional spatial information provided by 3D image data. For instance, guidance of minimally invasive procedures with CT or MRI data provides 3D spatial information and visualization of structures that are

  2. Diesel combustion and emissions formation using multiple 2-D imaging diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Dec, J.E. [Sandia National Labs., Livermore, CA (United States)

    1997-12-31

    Understanding how emissions are formed during diesel combustion is central to developing new engines that can comply with increasingly stringent emission standards while maintaining or improving performance levels. Laser-based planar imaging diagnostics are uniquely capable of providing the temporally and spatially resolved information required for this understanding. Using an optically accessible research engine, a variety of two-dimensional (2-D) imaging diagnostics have been applied to investigators of direct-injection (DI) diesel combustion and emissions formation. These optical measurements have included the following laser-sheet imaging data: Mie scattering to determine liquid-phase fuel distributions, Rayleigh scattering for quantitative vapor-phase-fuel/air mixture images, laser induced incandescence (LII) for relative soot concentrations, simultaneous LII and Rayleigh scattering for relative soot particle-size distributions, planar laser-induced fluorescence (PLIF) to obtain early PAH (polyaromatic hydrocarbon) distributions, PLIF images of the OH radical that show the diffusion flame structure, and PLIF images of the NO radical showing the onset of NO{sub x} production. In addition, natural-emission chemiluminescence images were obtained to investigate autoignition. The experimental setup is described, and the image data showing the most relevant results are presented. Then the conceptual model of diesel combustion is summarized in a series of idealized schematics depicting the temporal and spatial evolution of a reacting diesel fuel jet during the time period investigated. Finally, recent PLIF images of the NO distribution are presented and shown to support the timing and location of NO formation hypothesized from the conceptual model.

  3. [EOS imaging acquisition system : 2D/3D diagnostics of the skeleton].

    Science.gov (United States)

    Tarhan, T; Froemel, D; Meurer, A

    2015-12-01

    The application spectrum of the EOS imaging acquisition system is versatile. It is especially useful in the diagnostics and planning of corrective surgical procedures in complex orthopedic cases. The application is indicated when assessing deformities and malpositions of the spine, pelvis and lower extremities. It can also be used in the assessment and planning of hip and knee arthroplasty. For the first time physicians have the opportunity to conduct examinations of the whole body under weight-bearing conditions in order to anticipate the effects of a planned surgical procedure on the skeletal system as a whole and therefore on the posture of the patient. Compared to conventional radiographic examination techniques, such as x-ray or computed tomography, the patient is exposed to much less radiation. Therefore, the pediatric application of this technique can be described as reasonable.

  4. Diagnostic Value of 2D Strain Imaging In Patients with Suspected Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Daniela Teferici

    2014-03-01

    Conclusion: Ultrasound-based SI demonstrates a strong correlation with CAG and it has potential as a non-invasive diagnostic tool for detecting CAD in pts with chest pain and without wall motion abnormalities.

  5. Diagnostic value of 2D and 3D imaging in odontogenic maxillary sinusitis: a review of literature.

    Science.gov (United States)

    Shahbazian, M; Jacobs, R

    2012-04-01

    This review aims to explore whether 3D imaging offers an added value in diagnosis of odontogenic sinusitis. Odontogenic maxillary sinusitis accounts for approximately 10-12% of maxillary sinusitis cases. Proper diagnosis of odontogenic sinusitis is based on a thorough dental and medical examination and crucial to ensure therapeutic efficacy. To establish the odontogenic cause of maxillary sinusitis, 2D and 3D imaging modalities may be considered, each presenting distinct advantages and drawbacks. The available research indicates that 2D imaging modalities may often mask the origin of odontogenic maxillary sinusitis. This limitation is particularly evident in the maxillary molar region, stressing the need for 3D cross-sectional imaging. The advent of low-dose cone beam computed tomography in dentistry may be particularly useful when odontogenic maxillary sinusitis is not responsive to therapy. Yet, it seems that more research is needed to validate its use in odontogenic maxillary sinusitis.

  6. Image processing of 2D crystal images.

    Science.gov (United States)

    Arheit, Marcel; Castaño-Díez, Daniel; Thierry, Raphaël; Gipson, Bryant R; Zeng, Xiangyan; Stahlberg, Henning

    2013-01-01

    Electron crystallography of membrane proteins uses cryo-transmission electron microscopy to image frozen-hydrated 2D crystals. The processing of recorded images exploits the periodic arrangement of the structures in the images to extract the amplitudes and phases of diffraction spots in Fourier space. However, image imperfections require a crystal unbending procedure to be applied to the image before evaluation in Fourier space. We here describe the process of 2D crystal image unbending, using the 2dx software system.

  7. Automatic Contour Extraction from 2D Image

    Directory of Open Access Journals (Sweden)

    Panagiotis GIOANNIS

    2011-03-01

    Full Text Available Aim: To develop a method for automatic contour extraction from a 2D image. Material and Method: The method is divided in two basic parts where the user initially chooses the starting point and the threshold. Finally the method is applied to computed tomography of bone images. Results: An interesting method is developed which can lead to a successful boundary extraction of 2D images. Specifically data extracted from a computed tomography images can be used for 2D bone reconstruction. Conclusions: We believe that such an algorithm or part of it can be applied on several other applications for shape feature extraction in medical image analysis and generally at computer graphics.

  8. 2D microwave imaging reflectometer electronics

    Energy Technology Data Exchange (ETDEWEB)

    Spear, A. G.; Domier, C. W., E-mail: cwdomier@ucdavis.edu; Hu, X.; Muscatello, C. M.; Ren, X.; Luhmann, N. C. [Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2014-11-15

    A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program.

  9. 2D electron cyclotron emission imaging at ASDEX Upgrade (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Classen, I. G. J. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Boom, J. E.; Vries, P. C. de [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Suttrop, W.; Schmid, E.; Garcia-Munoz, M.; Schneider, P. A. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); Tobias, B.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Donne, A. J. H. [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Jaspers, R. J. E. [Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Park, H. K. [POSTECH, Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Munsat, T. [University of Colorado, Boulder, Colorado 80309 (United States)

    2010-10-15

    The newly installed electron cyclotron emission imaging diagnostic on ASDEX Upgrade provides measurements of the 2D electron temperature dynamics with high spatial and temporal resolution. An overview of the technical and experimental properties of the system is presented. These properties are illustrated by the measurements of the edge localized mode and the reversed shear Alfven eigenmode, showing both the advantage of having a two-dimensional (2D) measurement, as well as some of the limitations of electron cyclotron emission measurements. Furthermore, the application of singular value decomposition as a powerful tool for analyzing and filtering 2D data is presented.

  10. 3D/2D Registration of medical images

    OpenAIRE

    Tomaževič, D.

    2008-01-01

    The topic of this doctoral dissertation is registration of 3D medical images to corresponding projective 2D images, referred to as 3D/2D registration. There are numerous possible applications of 3D/2D registration in image-aided diagnosis and treatment. In most of the applications, 3D/2D registration provides the location and orientation of the structures in a preoperative 3D CT or MR image with respect to intraoperative 2D X-ray images. The proposed doctoral dissertation tries to find origin...

  11. Technique of Embedding Depth Maps into 2D Images

    Institute of Scientific and Technical Information of China (English)

    Kazutake Uehira; Hiroshi Unno; Youichi Takashima

    2014-01-01

    This paper proposes a new technique that is used to embed depth maps into corresponding 2-dimensional (2D) images. Since a 2D image and its depth map are integrated into one type of image format, they can be treated as if they were one 2D image. Thereby, it can reduce the amount of data in 3D images by half and simplify the processes for sending them through networks because the synchronization between images for the left and right eyes becomes unnecessary. We embed depth maps in the quantized discrete cosine transform (DCT) data of 2D images. The key to this technique is whether the depth maps could be embedded into 2D images without perceivably deteriorating their quality. We try to reduce their deterioration by compressing the depth map data by using the differences from the next pixel to the left. We assume that there is only one non-zero pixel at most on one horizontal line in the DCT block because the depth map values change abruptly. We conduct an experiment to evaluate the quality of the 2D images embedded with depth maps and find that satisfactory quality could be achieved.

  12. Framework for 2D-3D image fusion of infrared thermography with preoperative MRI.

    Science.gov (United States)

    Hoffmann, Nico; Weidner, Florian; Urban, Peter; Meyer, Tobias; Schnabel, Christian; Radev, Yordan; Schackert, Gabriele; Petersohn, Uwe; Koch, Edmund; Gumhold, Stefan; Steiner, Gerald; Kirsch, Matthias

    2017-01-23

    Multimodal medical image fusion combines information of one or more images in order to improve the diagnostic value. While previous applications mainly focus on merging images from computed tomography, magnetic resonance imaging (MRI), ultrasonic and single-photon emission computed tomography, we propose a novel approach for the registration and fusion of preoperative 3D MRI with intraoperative 2D infrared thermography. Image-guided neurosurgeries are based on neuronavigation systems, which further allow us track the position and orientation of arbitrary cameras. Hereby, we are able to relate the 2D coordinate system of the infrared camera with the 3D MRI coordinate system. The registered image data are now combined by calibration-based image fusion in order to map our intraoperative 2D thermographic images onto the respective brain surface recovered from preoperative MRI. In extensive accuracy measurements, we found that the proposed framework achieves a mean accuracy of 2.46 mm.

  13. Photorealistic image synthesis and camera validation from 2D images

    Science.gov (United States)

    Santos Ferrer, Juan C.; González Chévere, David; Manian, Vidya

    2014-06-01

    This paper presents a new 3D scene reconstruction technique using the Unity 3D game engine. The method presented here allow us to reconstruct the shape of simple objects and more complex ones from multiple 2D images, including infrared and digital images from indoor scenes and only digital images from outdoor scenes and then add the reconstructed object to the simulated scene created in Unity 3D, these scenes are then validated with real world scenes. The method used different cameras settings and explores different properties in the reconstructions of the scenes including light, color, texture, shapes and different views. To achieve the highest possible resolution, it was necessary the extraction of partial textures from visible surfaces. To recover the 3D shapes and the depth of simple objects that can be represented by the geometric bodies, there geometric characteristics were used. To estimate the depth of more complex objects the triangulation method was used, for this the intrinsic and extrinsic parameters were calculated using geometric camera calibration. To implement the methods mentioned above the Matlab tool was used. The technique presented here also let's us to simulate small simple videos, by reconstructing a sequence of multiple scenes of the video separated by small margins of time. To measure the quality of the reconstructed images and video scenes the Fast Low Band Model (FLBM) metric from the Video Quality Measurement (VQM) software was used. Low bandwidth perception based features include edges and motion.

  14. 2D/3D Image Registration using Regression Learning.

    Science.gov (United States)

    Chou, Chen-Rui; Frederick, Brandon; Mageras, Gig; Chang, Sha; Pizer, Stephen

    2013-09-01

    In computer vision and image analysis, image registration between 2D projections and a 3D image that achieves high accuracy and near real-time computation is challenging. In this paper, we propose a novel method that can rapidly detect an object's 3D rigid motion or deformation from a 2D projection image or a small set thereof. The method is called CLARET (Correction via Limited-Angle Residues in External Beam Therapy) and consists of two stages: registration preceded by shape space and regression learning. In the registration stage, linear operators are used to iteratively estimate the motion/deformation parameters based on the current intensity residue between the target projec-tion(s) and the digitally reconstructed radiograph(s) (DRRs) of the estimated 3D image. The method determines the linear operators via a two-step learning process. First, it builds a low-order parametric model of the image region's motion/deformation shape space from its prior 3D images. Second, using learning-time samples produced from the 3D images, it formulates the relationships between the model parameters and the co-varying 2D projection intensity residues by multi-scale linear regressions. The calculated multi-scale regression matrices yield the coarse-to-fine linear operators used in estimating the model parameters from the 2D projection intensity residues in the registration. The method's application to Image-guided Radiation Therapy (IGRT) requires only a few seconds and yields good results in localizing a tumor under rigid motion in the head and neck and under respiratory deformation in the lung, using one treatment-time imaging 2D projection or a small set thereof.

  15. Topology-Preserving Rigid Transformation of 2D Digital Images.

    Science.gov (United States)

    Ngo, Phuc; Passat, Nicolas; Kenmochi, Yukiko; Talbot, Hugues

    2014-02-01

    We provide conditions under which 2D digital images preserve their topological properties under rigid transformations. We consider the two most common digital topology models, namely dual adjacency and well-composedness. This paper leads to the proposal of optimal preprocessing strategies that ensure the topological invariance of images under arbitrary rigid transformations. These results and methods are proved to be valid for various kinds of images (binary, gray-level, label), thus providing generic and efficient tools, which can be used in particular in the context of image registration and warping.

  16. Building 3D scenes from 2D image sequences

    Science.gov (United States)

    Cristea, Paul D.

    2006-05-01

    Sequences of 2D images, taken by a single moving video receptor, can be fused to generate a 3D representation. This dynamic stereopsis exists in birds and reptiles, whereas the static binocular stereopsis is common in mammals, including humans. Most multimedia computer vision systems for stereo image capture, transmission, processing, storage and retrieval are based on the concept of binocularity. As a consequence, their main goal is to acquire, conserve and enhance pairs of 2D images able to generate a 3D visual perception in a human observer. Stereo vision in birds is based on the fusion of images captured by each eye, with previously acquired and memorized images from the same eye. The process goes on simultaneously and conjointly for both eyes and generates an almost complete all-around visual field. As a consequence, the baseline distance is no longer fixed, as in the case of binocular 3D view, but adjustable in accordance with the distance to the object of main interest, allowing a controllable depth effect. Moreover, the synthesized 3D scene can have a better resolution than each individual 2D image in the sequence. Compression of 3D scenes can be achieved, and stereo transmissions with lower bandwidth requirements can be developed.

  17. Interactive 2D to 3D stereoscopic image synthesis

    Science.gov (United States)

    Feldman, Mark H.; Lipton, Lenny

    2005-03-01

    Advances in stereoscopic display technologies, graphic card devices, and digital imaging algorithms have opened up new possibilities in synthesizing stereoscopic images. The power of today"s DirectX/OpenGL optimized graphics cards together with adapting new and creative imaging tools found in software products such as Adobe Photoshop, provide a powerful environment for converting planar drawings and photographs into stereoscopic images. The basis for such a creative process is the focus of this paper. This article presents a novel technique, which uses advanced imaging features and custom Windows-based software that utilizes the Direct X 9 API to provide the user with an interactive stereo image synthesizer. By creating an accurate and interactive world scene with moveable and flexible depth map altered textured surfaces, perspective stereoscopic cameras with both visible frustums and zero parallax planes, a user can precisely model a virtual three-dimensional representation of a real-world scene. Current versions of Adobe Photoshop provide a creative user with a rich assortment of tools needed to highlight elements of a 2D image, simulate hidden areas, and creatively shape them for a 3D scene representation. The technique described has been implemented as a Photoshop plug-in and thus allows for a seamless transition of these 2D image elements into 3D surfaces, which are subsequently rendered to create stereoscopic views.

  18. Volumetric elasticity imaging with a 2-D CMUT array.

    Science.gov (United States)

    Fisher, Ted G; Hall, Timothy J; Panda, Satchi; Richards, Michael S; Barbone, Paul E; Jiang, Jingfeng; Resnick, Jeff; Barnes, Steve

    2010-06-01

    This article reports the use of a two-dimensional (2-D) capacitive micro-machined ultrasound transducer (CMUT) to acquire radio-frequency (RF) echo data from relatively large volumes of a simple ultrasound phantom to compare three-dimensional (3-D) elasticity imaging methods. Typical 2-D motion tracking for elasticity image formation was compared with three different methods of 3-D motion tracking, with sum-squared difference (SSD) used as the similarity measure. Differences among the algorithms were the degree to which they tracked elevational motion: not at all (2-D search), planar search, combination of multiple planes and plane independent guided search. The cross-correlation between the predeformation and motion-compensated postdeformation RF echo fields was used to quantify motion tracking accuracy. The lesion contrast-to-noise ratio was used to quantify image quality. Tracking accuracy and strain image quality generally improved with increased tracking sophistication. When used as input for a 3-D modulus reconstruction, high quality 3-D displacement estimates yielded accurate and low noise modulus reconstruction.

  19. [Molecular diagnostics and imaging].

    Science.gov (United States)

    Fink, Christian; Fisseler-Eckhoff, Annette; Huss, Ralf; Nestle, Ursula

    2009-01-01

    Molecular diagnostic methods and biological imaging techniques can make a major contribution to tailoring patients' treatment needs with regard to medical, ethical and pharmaco-economic aspects. Modern diagnostic methods are already being used to help identify different sub-groups of patients with thoracic tumours who are most likely to benefit significantly from a particular type of treatment. This contribution looks at the most recent developments that have been made in the field of thoracic tumour diagnosis and analyses the pros and cons of new molecular and other imaging techniques in day-to-day clinical practice.

  20. Geometrical Correlation and Matching of 2d Image Shapes

    Science.gov (United States)

    Vizilter, Y. V.; Zheltov, S. Y.

    2012-07-01

    The problem of image correspondence measure selection for image comparison and matching is addressed. Many practical applications require image matching "just by shape" with no dependence on the concrete intensity or color values. Most popular technique for image shape comparison utilizes the mutual information measure based on probabilistic reasoning and information theory background. Another approach was proposed by Pytiev (so called "Pytiev morphology") based on geometrical and algebraic reasoning. In this framework images are considered as piecewise-constant 2D functions, tessellation of image frame by the set of non-intersected connected regions determines the "shape" of image and the projection of image onto the shape of other image is determined. Morphological image comparison is performed using the normalized morphological correlation coefficients. These coefficients estimate the closeness of one image to the shape of other image. Such image analysis technique can be characterized as an ""ntensity-to-geometry" matching. This paper generalizes the Pytiev morphological approach for obtaining the pure "geometry-to-geometry" matching techniques. The generalized intensity-geometrical correlation coefficient is proposed including the linear correlation coefficient and the square of Pytiev correlation coefficient as its partial cases. The morphological shape correlation coefficient is proposed based on the statistical averaging of images with the same shape. Centered morphological correlation coefficient is obtained under the condition of intensity centering of averaged images. Two types of symmetric geometrical normalized correlation coefficients are proposed for comparison of shape-tessellations. The technique for correlation and matching of shapes with ordered intensities is proposed with correlation measures invariant to monotonous intensity transformations. The quality of proposed geometrical correlation measures is experimentally estimated in the task of

  1. A Volume Rendering Algorithm for Sequential 2D Medical Images

    Institute of Scientific and Technical Information of China (English)

    吕忆松; 陈亚珠

    2002-01-01

    Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics.To help physicians fully understand deep-seated human organs and focuses(e.g.a tumour)as 3D structures.in this paper,we present a modified volume rendering algorithm to render volumetric data,Using this method.the projection images of structures of interest from different viewing directions can be obtained satisfactorily.By rotating the light source and the observer eyepoint,this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time.Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.

  2. A novel point cloud registration using 2D image features

    Science.gov (United States)

    Lin, Chien-Chou; Tai, Yen-Chou; Lee, Jhong-Jin; Chen, Yong-Sheng

    2017-01-01

    Since a 3D scanner only captures a scene of a 3D object at a time, a 3D registration for multi-scene is the key issue of 3D modeling. This paper presents a novel and an efficient 3D registration method based on 2D local feature matching. The proposed method transforms the point clouds into 2D bearing angle images and then uses the 2D feature based matching method, SURF, to find matching pixel pairs between two images. The corresponding points of 3D point clouds can be obtained by those pixel pairs. Since the corresponding pairs are sorted by their distance between matching features, only the top half of the corresponding pairs are used to find the optimal rotation matrix by the least squares approximation. In this paper, the optimal rotation matrix is derived by orthogonal Procrustes method (SVD-based approach). Therefore, the 3D model of an object can be reconstructed by aligning those point clouds with the optimal transformation matrix. Experimental results show that the accuracy of the proposed method is close to the ICP, but the computation cost is reduced significantly. The performance is six times faster than the generalized-ICP algorithm. Furthermore, while the ICP requires high alignment similarity of two scenes, the proposed method is robust to a larger difference of viewing angle.

  3. Image Appraisal for 2D and 3D Electromagnetic Inversion

    Energy Technology Data Exchange (ETDEWEB)

    Alumbaugh, D.L.; Newman, G.A.

    1999-01-28

    Linearized methods are presented for appraising image resolution and parameter accuracy in images generated with two and three dimensional non-linear electromagnetic inversion schemes. When direct matrix inversion is employed, the model resolution and posterior model covariance matrices can be directly calculated. A method to examine how the horizontal and vertical resolution varies spatially within the electromagnetic property image is developed by examining the columns of the model resolution matrix. Plotting the square root of the diagonal of the model covariance matrix yields an estimate of how errors in the inversion process such as data noise and incorrect a priori assumptions about the imaged model map into parameter error. This type of image is shown to be useful in analyzing spatial variations in the image sensitivity to the data. A method is analyzed for statistically estimating the model covariance matrix when the conjugate gradient method is employed rather than a direct inversion technique (for example in 3D inversion). A method for calculating individual columns of the model resolution matrix using the conjugate gradient method is also developed. Examples of the image analysis techniques are provided on 2D and 3D synthetic cross well EM data sets, as well as a field data set collected at the Lost Hills Oil Field in Central California.

  4. Modifications to the synthetic aperture microwave imaging diagnostic

    Science.gov (United States)

    Brunner, K. J.; Chorley, J. C.; Dipper, N. A.; Naylor, G.; Sharples, R. M.; Taylor, G.; Thomas, D. A.; Vann, R. G. L.

    2016-11-01

    The synthetic aperture microwave imaging diagnostic has been operating on the MAST experiment since 2011. It has provided the first 2D images of B-X-O mode conversion windows and showed the feasibility of conducting 2D Doppler back-scattering experiments. The diagnostic heavily relies on field programmable gate arrays to conduct its work. Recent successes and newly gained experience with the diagnostic have led us to modify it. The enhancements will enable pitch angle profile measurements, O and X mode separation, and the continuous acquisition of 2D DBS data. The diagnostic has also been installed on the NSTX-U and is acquiring data since May 2016.

  5. 2D magnetic nanoparticle imaging using magnetization response second harmonic

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Saburo, E-mail: tanakas@ens.tut.ac.jp [Toyohashi University of Technology, 1-1 Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Murata, Hayaki; Oishi, Tomoya; Suzuki, Toshifumi [Toyohashi University of Technology, 1-1 Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Zhang, Yi [Peter Gruenberg Institute, Forschungszentrum Juelich, Juelich D-52425 (Germany)

    2015-06-01

    A detection method and an imaging technique for magnetic nanoparticles (MNPs) have been investigated. In MNP detection and in magnetic particle imaging (MPI), the most commonly employed method is the detection of the odd harmonics of the magnetization response. We examined the advantage of using the second harmonic response when applying an AC magnetic modulation field and a DC bias field. If the magnetization response is detected by a Cu-wound-coil detection system, the output voltage from the coil is proportional to the change in the flux, dϕ/dt. Thus, the dependence of the derivative of the magnetization, M, on an AC magnetic modulation field and a DC bias field were calculated and investigated. The calculations were in good agreement with the experimental results. We demonstrated that the use of the second harmonic response for the detection of MNPs has an advantage compared with the usage of the third harmonic response, when the Cu-wound-coil detection system is employed and the amplitude of the ratio of the AC modulation field and a knee field H{sub ac}/H{sub k} is less than 2. We also constructed a 2D MPI scanner using a pair of permanent ring magnets with a bore of ϕ80 mm separated by 90 mm. The magnets generated a gradient of G{sub z}=3.17 T/m transverse to the imaging bore and G{sub x}=1.33 T/m along the longitudinal axis. An original concentrated 10 μl Resovist solution in a ϕ2×3 mm{sup 2} vessel was used as a sample, and it was imaged by the scanner. As a result, a 2D contour map image could be successfully generated using the method with a lock-in amplifier.

  6. Joint 2D and 3D phase processing for quantitative susceptibility mapping: application to 2D echo-planar imaging.

    Science.gov (United States)

    Wei, Hongjiang; Zhang, Yuyao; Gibbs, Eric; Chen, Nan-Kuei; Wang, Nian; Liu, Chunlei

    2017-04-01

    Quantitative susceptibility mapping (QSM) measures tissue magnetic susceptibility and typically relies on time-consuming three-dimensional (3D) gradient-echo (GRE) MRI. Recent studies have shown that two-dimensional (2D) multi-slice gradient-echo echo-planar imaging (GRE-EPI), which is commonly used in functional MRI (fMRI) and other dynamic imaging techniques, can also be used to produce data suitable for QSM with much shorter scan times. However, the production of high-quality QSM maps is difficult because data obtained by 2D multi-slice scans often have phase inconsistencies across adjacent slices and strong susceptibility field gradients near air-tissue interfaces. To address these challenges in 2D EPI-based QSM studies, we present a new data processing procedure that integrates 2D and 3D phase processing. First, 2D Laplacian-based phase unwrapping and 2D background phase removal are performed to reduce phase inconsistencies between slices and remove in-plane harmonic components of the background phase. This is followed by 3D background phase removal for the through-plane harmonic components. The proposed phase processing was evaluated with 2D EPI data obtained from healthy volunteers, and compared against conventional 3D phase processing using the same 2D EPI datasets. Our QSM results were also compared with QSM values from time-consuming 3D GRE data, which were taken as ground truth. The experimental results show that this new 2D EPI-based QSM technique can produce quantitative susceptibility measures that are comparable with those of 3D GRE-based QSM across different brain regions (e.g. subcortical iron-rich gray matter, cortical gray and white matter). This new 2D EPI QSM reconstruction method is implemented within STI Suite, which is a comprehensive shareware for susceptibility imaging and quantification. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  7. FPGA implementation of filtered image using 2D Gaussian filter

    Directory of Open Access Journals (Sweden)

    Leila kabbai

    2016-07-01

    Full Text Available Image filtering is one of the very useful techniques in image processing and computer vision. It is used to eliminate useless details and noise from an image. In this paper, a hardware implementation of image filtered using 2D Gaussian Filter will be present. The Gaussian filter architecture will be described using a different way to implement convolution module. Thus, multiplication is in the heart of convolution module, for this reason, three different ways to implement multiplication operations will be presented. The first way is done using the standard method. The second way uses Field Programmable Gate Array (FPGA features Digital Signal Processor (DSP to ensure and make fast the scalability of the effective FPGA resource and then to speed up calculation. The third way uses real multiplier for more precision and a the maximum uses of FPGA resources. In this paper, we compare the image quality of hardware (VHDL and software (MATLAB implementation using the Peak Signal-to-Noise Ratio (PSNR. Also, the FPGA resource usage for different sizes of Gaussian kernel will be presented in order to provide a comparison between fixed-point and floating point implementations.

  8. Efficient Sample Delay Calculation for 2-D and 3-D Ultrasound Imaging.

    Science.gov (United States)

    Ibrahim, Aya; Hager, Pascal A; Bartolini, Andrea; Angiolini, Federico; Arditi, Marcel; Thiran, Jean-Philippe; Benini, Luca; De Micheli, Giovanni

    2017-08-01

    Ultrasound imaging is a reference medical diagnostic technique, thanks to its blend of versatility, effectiveness, and moderate cost. The core computation of all ultrasound imaging methods is based on simple formulae, except for those required to calculate acoustic propagation delays with high precision and throughput. Unfortunately, advanced three-dimensional (3-D) systems require the calculation or storage of billions of such delay values per frame, which is a challenge. In 2-D systems, this requirement can be four orders of magnitude lower, but efficient computation is still crucial in view of low-power implementations that can be battery-operated, enabling usage in numerous additional scenarios. In this paper, we explore two smart designs of the delay generation function. To quantify their hardware cost, we implement them on FPGA and study their footprint and performance. We evaluate how these architectures scale to different ultrasound applications, from a low-power 2-D system to a next-generation 3-D machine. When using numerical approximations, we demonstrate the ability to generate delay values with sufficient throughput to support 10 000-channel 3-D imaging at up to 30 fps while using 63% of a Virtex 7 FPGA, requiring 24 MB of external memory accessed at about 32 GB/s bandwidth. Alternatively, with similar FPGA occupation, we show an exact calculation method that reaches 24 fps on 1225-channel 3-D imaging and does not require external memory at all. Both designs can be scaled to use a negligible amount of resources for 2-D imaging in low-power applications and for ultrafast 2-D imaging at hundreds of frames per second.

  9. Design of the 2D electron cyclotron emission imaging instrument for the J-TEXT tokamak

    Science.gov (United States)

    Pan, X. M.; Yang, Z. J.; Ma, X. D.; Zhu, Y. L.; Luhmann, N. C.; Domier, C. W.; Ruan, B. W.; Zhuang, G.

    2016-11-01

    A new 2D Electron Cyclotron Emission Imaging (ECEI) diagnostic is being developed for the J-TEXT tokamak. It will provide the 2D electron temperature information with high spatial, temporal, and temperature resolution. The new ECEI instrument is being designed to support fundamental physics investigations on J-TEXT including MHD, disruption prediction, and energy transport. The diagnostic contains two dual dipole antenna arrays corresponding to F band (90-140 GHz) and W band (75-110 GHz), respectively, and comprises a total of 256 channels. The system can observe the same magnetic surface at both the high field side and low field side simultaneously. An advanced optical system has been designed which permits the two arrays to focus on a wide continuous region or two radially separate regions with high imaging spatial resolution. It also incorporates excellent field curvature correction with field curvature adjustment lenses. An overview of the diagnostic and the technical progress including the new remote control technique are presented.

  10. Design of the 2D electron cyclotron emission imaging instrument for the J-TEXT tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Pan, X. M.; Yang, Z. J., E-mail: yangzj@hust.edu.cn; Ma, X. D.; Ruan, B. W.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Zhu, Y. L. [School of Physics, University of Science and Technology of China, Anhui 230026 (China); Luhmann, N. C.; Domier, C. W. [Davis Millimeter Wave Research Center, University of California, Davis, California 95616 (United States)

    2016-11-15

    A new 2D Electron Cyclotron Emission Imaging (ECEI) diagnostic is being developed for the J-TEXT tokamak. It will provide the 2D electron temperature information with high spatial, temporal, and temperature resolution. The new ECEI instrument is being designed to support fundamental physics investigations on J-TEXT including MHD, disruption prediction, and energy transport. The diagnostic contains two dual dipole antenna arrays corresponding to F band (90-140 GHz) and W band (75-110 GHz), respectively, and comprises a total of 256 channels. The system can observe the same magnetic surface at both the high field side and low field side simultaneously. An advanced optical system has been designed which permits the two arrays to focus on a wide continuous region or two radially separate regions with high imaging spatial resolution. It also incorporates excellent field curvature correction with field curvature adjustment lenses. An overview of the diagnostic and the technical progress including the new remote control technique are presented.

  11. Filters in 2D and 3D Cardiac SPECT Image Processing

    Directory of Open Access Journals (Sweden)

    Maria Lyra

    2014-01-01

    Full Text Available Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the degradation of the image. SPECT images are then reconstructed, either by filter back projection (FBP analytical technique or iteratively, by algebraic methods. The aim of this study is to review filters in cardiac 2D, 3D, and 4D SPECT applications and how these affect the image quality mirroring the diagnostic accuracy of SPECT images. Several filters, including the Hanning, Butterworth, and Parzen filters, were evaluated in combination with the two reconstruction methods as well as with a specified MatLab program. Results showed that for both 3D and 4D cardiac SPECT the Butterworth filter, for different critical frequencies and orders, produced the best results. Between the two reconstruction methods, the iterative one might be more appropriate for cardiac SPECT, since it improves lesion detectability due to the significant improvement of image contrast.

  12. Filters in 2D and 3D Cardiac SPECT Image Processing.

    Science.gov (United States)

    Lyra, Maria; Ploussi, Agapi; Rouchota, Maritina; Synefia, Stella

    2014-01-01

    Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT) evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the degradation of the image. SPECT images are then reconstructed, either by filter back projection (FBP) analytical technique or iteratively, by algebraic methods. The aim of this study is to review filters in cardiac 2D, 3D, and 4D SPECT applications and how these affect the image quality mirroring the diagnostic accuracy of SPECT images. Several filters, including the Hanning, Butterworth, and Parzen filters, were evaluated in combination with the two reconstruction methods as well as with a specified MatLab program. Results showed that for both 3D and 4D cardiac SPECT the Butterworth filter, for different critical frequencies and orders, produced the best results. Between the two reconstruction methods, the iterative one might be more appropriate for cardiac SPECT, since it improves lesion detectability due to the significant improvement of image contrast.

  13. [Diagnostic imaging of lying].

    Science.gov (United States)

    Lass, Piotr; Sławek, Jarosław; Sitek, Emilia; Szurowska, Edyta; Zimmermann, Agnieszka

    2013-01-01

    Functional diagnostic imaging has been applied in neuropsychology for more than two decades. Nowadays, the functional magnetic resonance (fMRI) seems to be the most important technique. Brain imaging in lying has been performed and discussed since 2001. There are postulates to use fMRI for forensic purposes, as well as commercially, e.g. testing the loyalty of employees, especially because of the limitations of traditional polygraph in some cases. In USA fMRI is performed in truthfulness/lying assessment by at least two commercial companies. Those applications are a matter of heated debate of practitioners, lawyers and specialists of ethics. The opponents of fMRI use for forensic purposes indicate the lack of common agreement on it and the lack of wide recognition and insufficient standardisation. Therefore it cannot serve as a forensic proof, yet. However, considering the development of MRI and a high failure rate of traditional polygraphy, forensic applications of MRI seem to be highly probable in future.

  14. Maximizing entropy of image models for 2-D constrained coding

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Danieli, Matteo; Burini, Nino

    2010-01-01

    This paper considers estimating and maximizing the entropy of two-dimensional (2-D) fields with application to 2-D constrained coding. We consider Markov random fields (MRF), which have a non-causal description, and the special case of Pickard random fields (PRF). The PRF are 2-D causal finite...... context models, which define stationary probability distributions on finite rectangles and thus allow for calculation of the entropy. We consider two binary constraints and revisit the hard square constraint given by forbidding neighboring 1s and provide novel results for the constraint that no uniform 2...... £ 2 squares contains all 0s or all 1s. The maximum values of the entropy for the constraints are estimated and binary PRF satisfying the constraint are characterized and optimized w.r.t. the entropy. The maximum binary PRF entropy is 0.839 bits/symbol for the no uniform squares constraint. The entropy...

  15. WE-AB-BRA-07: Quantitative Evaluation of 2D-2D and 2D-3D Image Guided Radiation Therapy for Clinical Trial Credentialing, NRG Oncology/RTOG

    Energy Technology Data Exchange (ETDEWEB)

    Giaddui, T; Yu, J; Xiao, Y [Thomas Jefferson University, Philadelphia, PA (United States); Jacobs, P [MIM Software, Inc, Cleavland, Ohio (United States); Manfredi, D; Linnemann, N [IROC Philadelphia, RTQA Center, Philadelphia, PA (United States)

    2015-06-15

    Purpose: 2D-2D kV image guided radiation therapy (IGRT) credentialing evaluation for clinical trial qualification was historically qualitative through submitting screen captures of the fusion process. However, as quantitative DICOM 2D-2D and 2D-3D image registration tools are implemented in clinical practice for better precision, especially in centers that treat patients with protons, better IGRT credentialing techniques are needed. The aim of this work is to establish methodologies for quantitatively reviewing IGRT submissions based on DICOM 2D-2D and 2D-3D image registration and to test the methodologies in reviewing 2D-2D and 2D-3D IGRT submissions for RTOG/NRG Oncology clinical trials qualifications. Methods: DICOM 2D-2D and 2D-3D automated and manual image registration have been tested using the Harmony tool in MIM software. 2D kV orthogonal portal images are fused with the reference digital reconstructed radiographs (DRR) in the 2D-2D registration while the 2D portal images are fused with DICOM planning CT image in the 2D-3D registration. The Harmony tool allows alignment of the two images used in the registration process and also calculates the required shifts. Shifts calculated using MIM are compared with those submitted by institutions for IGRT credentialing. Reported shifts are considered to be acceptable if differences are less than 3mm. Results: Several tests have been performed on the 2D-2D and 2D-3D registration. The results indicated good agreement between submitted and calculated shifts. A workflow for reviewing these IGRT submissions has been developed and will eventually be used to review IGRT submissions. Conclusion: The IROC Philadelphia RTQA center has developed and tested a new workflow for reviewing DICOM 2D-2D and 2D-3D IGRT credentialing submissions made by different cancer clinical centers, especially proton centers. NRG Center for Innovation in Radiation Oncology (CIRO) and IROC RTQA center continue their collaborative efforts to enhance

  16. Design of a quadratic filter for contrast - assisted ultrasonic imaging based on 2D gaussian filters

    Directory of Open Access Journals (Sweden)

    Tosaporn Nilmanee

    2010-05-01

    Full Text Available We present a novel design of quadratic filters (QFs in the frequency domain in order to improve the quality of contrastassisted ultrasound images for medical diagnosis. The QF is designed as a 2D linear-phase filter. In addition, the magnitude is based on the sum of two 2D Gaussian filters. The centers of the Gaussian filters are placed at the locations where the power strength of signals from ultrasound contrast agent over surrounding tissue is maximal. The design parameters consist of two centers and a standard deviation (SD of the Gaussian filters. The coefficients of the QF are obtained using the inverse discreteFourier transform. The QFs from the proposed design method are evaluated using in vivo ultrasound data, i.e., the kidney of aguinea pig. We find that the appropriate SD and two center points of the QF for the in vivo data are at 0.34, (3.30, 3.30 and (-3.30,-3.30 MHz, respectively. Results show that the images produced from the output signals of the new design are superior to theoriginal B-mode both in terms of contrast and spatial resolution. The quadratic image provides clear visualization of thekidney shape and large vascular structures inside the kidney. The contrast-to-tissue ratio value of quadratic image is 24.8 dBcompared to -1.5 dB from the B-mode image. In addition, we can use this new design approach as an efficient tool to furtherimprove the QF in producing better contrast-assisted ultrasound images for medical diagnostic purposes.

  17. Extending Ripley's K-Function to Quantify Aggregation in 2-D Grayscale Images.

    Directory of Open Access Journals (Sweden)

    Mohamed Amgad

    Full Text Available In this work, we describe the extension of Ripley's K-function to allow for overlapping events at very high event densities. We show that problematic edge effects introduce significant bias to the function at very high densities and small radii, and propose a simple correction method that successfully restores the function's centralization. Using simulations of homogeneous Poisson distributions of events, as well as simulations of event clustering under different conditions, we investigate various aspects of the function, including its shape-dependence and correspondence between true cluster radius and radius at which the K-function is maximized. Furthermore, we validate the utility of the function in quantifying clustering in 2-D grayscale images using three modalities: (i Simulations of particle clustering; (ii Experimental co-expression of soluble and diffuse protein at varying ratios; (iii Quantifying chromatin clustering in the nuclei of wt and crwn1 crwn2 mutant Arabidopsis plant cells, using a previously-published image dataset. Overall, our work shows that Ripley's K-function is a valid abstract statistical measure whose utility extends beyond the quantification of clustering of non-overlapping events. Potential benefits of this work include the quantification of protein and chromatin aggregation in fluorescent microscopic images. Furthermore, this function has the potential to become one of various abstract texture descriptors that are utilized in computer-assisted diagnostics in anatomic pathology and diagnostic radiology.

  18. GEOMETRICAL CORRELATION AND MATCHING OF 2D IMAGE SHAPES

    OpenAIRE

    Y. V. Vizilter; S. Y. Zheltov

    2012-01-01

    The problem of image correspondence measure selection for image comparison and matching is addressed. Many practical applications require image matching "just by shape" with no dependence on the concrete intensity or color values. Most popular technique for image shape comparison utilizes the mutual information measure based on probabilistic reasoning and information theory background. Another approach was proposed by Pytiev (so called "Pytiev morphology") based on geometrical and algebraic r...

  19. 2-D Tissue Motion Compensation of Synthetic Transmit Aperture Images

    DEFF Research Database (Denmark)

    Gammelmark, Kim Løkke; Jensen, Jørgen Arendt

    2014-01-01

    images recorded using the same emission sequence. The velocity and direction of the motion are found by crosscorrelating short high-resolution lines beamformed along selected angles. The motion acquisition is interleaved with the regular B-mode emissions in STA imaging, and the motion compensation...... be compensated for, and that doing so yields a significant increase in image quality....

  20. Visual grading of 2D and 3D functional MRI compared with image-based descriptive measures

    Energy Technology Data Exchange (ETDEWEB)

    Ragnehed, Mattias [Linkoeping University, Division of Radiological Sciences, Radiology, IMH, Linkoeping (Sweden); Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences, Division of Radiological Sciences/Radiology, Faculty of Health Sciences, Linkoeping (Sweden); Leinhard, Olof Dahlqvist; Pihlsgaard, Johan; Lundberg, Peter [Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden); Linkoeping University, Division of Radiological Sciences, Radiation Physics, IMH, Linkoeping (Sweden); Wirell, Staffan [Linkoeping University, Division of Radiological Sciences, Radiology, IMH, Linkoeping (Sweden); Linkoeping University Hospital, Department of Radiology, Linkoeping (Sweden); Soekjer, Hannibal; Faegerstam, Patrik [Linkoeping University Hospital, Department of Radiology, Linkoeping (Sweden); Jiang, Bo [Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden); Smedby, Oerjan; Engstroem, Maria [Linkoeping University, Division of Radiological Sciences, Radiology, IMH, Linkoeping (Sweden); Linkoeping University, Center for Medical Image Science and Visualization, CMIV, Linkoeping (Sweden)

    2010-03-15

    A prerequisite for successful clinical use of functional magnetic resonance imaging (fMRI) is the selection of an appropriate imaging sequence. The aim of this study was to compare 2D and 3D fMRI sequences using different image quality assessment methods. Descriptive image measures, such as activation volume and temporal signal-to-noise ratio (TSNR), were compared with results from visual grading characteristics (VGC) analysis of the fMRI results. Significant differences in activation volume and TSNR were not directly reflected by differences in VGC scores. The results suggest that better performance on descriptive image measures is not always an indicator of improved diagnostic quality of the fMRI results. In addition to descriptive image measures, it is important to include measures of diagnostic quality when comparing different fMRI data acquisition methods. (orig.)

  1. TU-CD-207-08: Intrinsic Image Quality Comparison of Synthesized 2-D and FFDM Images

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, J; Wells, J; Samei, E [Clinical Imaging Physics Group, Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: With the combined interest of managing patient dose, maintaining or improving image quality, and maintaining or improving the diagnostic utility of mammographic data, this study aims to compare the intrinsic image quality of Hologic’s synthesized 2-D (C-View) and 2-D FFDM images in terms of resolution, contrast, and noise. Methods: This study utilized a novel 3-D printed anthropomorphic breast phantom in addition to the American College of Radiology (ACR) mammography accreditation phantom. Analysis of the 3-D anthropomorphic phantom included visual assessment of resolution and analysis of the normalized noise power spectrum. Analysis of the ACR phantom included both visual inspection and objective automated analysis using in-house software. The software incorporates image- and object-specific CNR visibility thresholds which account for image characteristics such as noise texture which affect object visualization. T- test statistical analysis was also performed on ACR phantom scores. Results: The spatial resolution of C-View images is markedly lower (at least 50% worse) than that of FFDM. And while this is generally associated with the benefit of reduced relative noise magnitude, the noise in C-View images tends to have a more mottled (predominantly low-frequency) texture. In general, for high contrast objects, C-View provides superior visualization over FFDM; however this benefit diminishes for low contrast objects and is applicable only to objects that are sufficiently larger than the spatial resolution threshold. Based on both observer and automated ACR phantom analysis, between 50–70% of C-View images failed to meet ACR minimum accreditation requirements – primarily due to insufficient (unbroken) fiber visibility. Conclusion: Compared to FFDM, C-View offers better depiction of objects of certain size and contrast, but provides poorer overall resolution and noise properties. Based on these findings, the utilization of C-View images in the clinical

  2. 2D Optical Streaking for Ultra-Short Electron Beam Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Y.T.; Huang, Z.; Wang, L.; /SLAC

    2011-12-14

    field ionization, which occurs in plasma case, gases species with high field ionization threshold should be considered. For a linear polarized laser, the kick to the ionized electrons depends on the phase of the laser when the electrons are born and the unknown timing jitter between the electron beam and laser beam makes the data analysis very difficult. Here we propose to use a circular polarized laser to do a 2-dimensional (2D) streaking (both x and y) and measure the bunch length from the angular distribution on the screen, where the phase jitter causes only a rotation of the image on the screen without changing of the relative angular distribution. Also we only need to know the laser wavelength for calibration. A similar circular RF deflecting mode was used to measure long bunches. We developed a numerical particle-in-Cell (PIC) code to study the dynamics of ionization electrons with the high energy beam and the laser beam.

  3. 3D-2D registration of cerebral angiograms: a method and evaluation on clinical images.

    Science.gov (United States)

    Mitrovic, Uroš; Špiclin, Žiga; Likar, Boštjan; Pernuš, Franjo

    2013-08-01

    Endovascular image-guided interventions (EIGI) involve navigation of a catheter through the vasculature followed by application of treatment at the site of anomaly using live 2D projection images for guidance. 3D images acquired prior to EIGI are used to quantify the vascular anomaly and plan the intervention. If fused with the information of live 2D images they can also facilitate navigation and treatment. For this purpose 3D-2D image registration is required. Although several 3D-2D registration methods for EIGI achieve registration accuracy below 1 mm, their clinical application is still limited by insufficient robustness or reliability. In this paper, we propose a 3D-2D registration method based on matching a 3D vasculature model to intensity gradients of live 2D images. To objectively validate 3D-2D registration methods, we acquired a clinical image database of 10 patients undergoing cerebral EIGI and established "gold standard" registrations by aligning fiducial markers in 3D and 2D images. The proposed method had mean registration accuracy below 0.65 mm, which was comparable to tested state-of-the-art methods, and execution time below 1 s. With the highest rate of successful registrations and the highest capture range the proposed method was the most robust and thus a good candidate for application in EIGI.

  4. Detection of sinkholes using 2D electrical resistivity imaging

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2002-07-01

    Full Text Available Sinkholes in dolomitic areas are notoriously difficult geophysical targets, and selecting an appropriate geophysical solution is not straightforward. Electrical resistivity imaging or tomography (RESTOM) is well suited to mapping sinkholes because...

  5. Fast 2-D 8×8 discrete cosine transform algorithm for image coding

    Institute of Scientific and Technical Information of China (English)

    JI XiuHua; ZHANG CaiMing; WANG JiaYe; BOEY S. H.

    2009-01-01

    A new fast two-dimension 8×8 discrete cosine transform (2D 8×8 DCT) algorithm based on the charac-teristics of the basic images of 2D DCT is presented. The new algorithm computes each DCT coefficient in turn more independently. Hence, the new algorithm is suitable for 2D DCT pruning algorithm of prun-ing away any number of high-frequency components of 2D DCT. The proposed pruning algorithm ls more efficient than the existing pruning 2D DCT algorithms in terms of the number of arithmetic opera-tions, especially the number of multiplications required in the computation.

  6. Imaging Techniques for Microwave Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Donne, T. [FOM-Institute for Plasma Physics Rijnhuizen, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Luhmann Jr, N.C. [University of California, Davis, CA 95616 (United States); Park, H.K. [POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Tobias, B.

    2011-07-01

    Advances in microwave technology have made it possible to develop a new generation of microwave imaging diagnostics for measuring the parameters of magnetic fusion devices. The most prominent of these diagnostics is electron cyclotron emission imaging (ECE-I). After the first generation of ECE-I diagnostics utilized at the TEXT-U, RTP and TEXTOR tokamaks and the LHD stellarator, new systems have recently come into operation on ASDEX-UG and DIII-D, soon to be followed by a system on KSTAR. The DIII-D and KSTAR systems feature dual imaging arrays that observe different parts of the plasma. The ECE-I diagnostic yields two-dimensional movies of the electron temperature in the plasma and has given already new insights into the physics of sawtooth oscillations, tearing modes and edge localized modes. Microwave Imaging Reflectometry (MIR) is used on LHD to measure electron density fluctuations. A pilot MIR system has been tested at TEXTOR and, based on the promising results, a new system is now under design for KSTAR. The system at TEXTOR was used to measure the plasma rotation velocity. The system at KSTAR and also the one on LHD will be/are used for measuring the profile of the electron density fluctuations in the plasma. Other microwave imaging diagnostics are phase imaging interferometry, and imaging microwave scattering. The emphasis in this paper will be largely focused on ECE-I. First an overview of the advances in microwave technology are discussed, followed by a description of a typical ECE-I system along with some typical experimental results. Also the utilization of imaging techniques in other types of microwave diagnostics will be briefly reviewed. This document is composed of the slides of the presentation. (authors)

  7. Beamforming Scheme for 2D Displacement Estimation in Ultrasound Imaging

    Directory of Open Access Journals (Sweden)

    Philippe Delachartre

    2005-05-01

    Full Text Available We propose a beamforming scheme for ultrasound imaging leading to the generation of two sets of images, one with oscillations only in the axial direction and one with oscillations only in the lateral direction. Applied to tissue elasticity imaging, this leads to the development of a specific displacement estimation technique that is capable of accurate estimation of two components of the displacement. The mean standard deviation for the axial displacement estimates is 0.0219 times the wavelength of the axial oscillations λz, and for the lateral estimates, it is equal to 0.0164 times the wavelength of the lateral oscillations λx. The method is presented and its feasibility is clearly established by a simulation work.

  8. Multifractal analysis of 2D gray soil images

    Science.gov (United States)

    González-Torres, Ivan; Losada, Juan Carlos; Heck, Richard; Tarquis, Ana M.

    2015-04-01

    Soil structure, understood as the spatial arrangement of soil pores, is one of the key factors in soil modelling processes. Geometric properties of individual and interpretation of the morphological parameters of pores can be estimated from thin sections or 3D Computed Tomography images (Tarquis et al., 2003), but there is no satisfactory method to binarized these images and quantify the complexity of their spatial arrangement (Tarquis et al., 2008, Tarquis et al., 2009; Baveye et al., 2010). The objective of this work was to apply a multifractal technique, their singularities (α) and f(α) spectra, to quantify it without applying any threshold (Gónzalez-Torres, 2014). Intact soil samples were collected from four horizons of an Argisol, formed on the Tertiary Barreiras group of formations in Pernambuco state, Brazil (Itapirema Experimental Station). The natural vegetation of the region is tropical, coastal rainforest. From each horizon, showing different porosities and spatial arrangements, three adjacent samples were taken having a set of twelve samples. The intact soil samples were imaged using an EVS (now GE Medical. London, Canada) MS-8 MicroCT scanner with 45 μm pixel-1 resolution (256x256 pixels). Though some samples required paring to fit the 64 mm diameter imaging tubes, field orientation was maintained. References Baveye, P.C., M. Laba, W. Otten, L. Bouckaert, P. Dello, R.R. Goswami, D. Grinev, A. Houston, Yaoping Hu, Jianli Liu, S. Mooney, R. Pajor, S. Sleutel, A. Tarquis, Wei Wang, Qiao Wei, Mehmet Sezgin. Observer-dependent variability of the thresholding step in the quantitative analysis of soil images and X-ray microtomography data. Geoderma, 157, 51-63, 2010. González-Torres, Iván. Theory and application of multifractal analysis methods in images for the study of soil structure. Master thesis, UPM, 2014. Tarquis, A.M., R.J. Heck, J.B. Grau; J. Fabregat, M.E. Sanchez and J.M. Antón. Influence of Thresholding in Mass and Entropy Dimension of 3-D

  9. The agreement between 3D, standard 2D and triplane 2D speckle tracking: effects of image quality and 3D volume rate.

    Science.gov (United States)

    Trache, Tudor; Stöbe, Stephan; Tarr, Adrienn; Pfeiffer, Dietrich; Hagendorff, Andreas

    2014-12-01

    Comparison of 3D and 2D speckle tracking performed on standard 2D and triplane 2D datasets of normal and pathological left ventricular (LV) wall-motion patterns with a focus on the effect that 3D volume rate (3DVR), image quality and tracking artifacts have on the agreement between 2D and 3D speckle tracking. 37 patients with normal LV function and 18 patients with ischaemic wall-motion abnormalities underwent 2D and 3D echocardiography, followed by offline speckle tracking measurements. The values of 3D global, regional and segmental strain were compared with the standard 2D and triplane 2D strain values. Correlation analysis with the LV ejection fraction (LVEF) was also performed. The 3D and 2D global strain values correlated good in both normally and abnormally contracting hearts, though systematic differences between the two methods were observed. Of the 3D strain parameters, the area strain showed the best correlation with the LVEF. The numerical agreement of 3D and 2D analyses varied significantly with the volume rate and image quality of the 3D datasets. The highest correlation between 2D and 3D peak systolic strain values was found between 3D area and standard 2D longitudinal strain. Regional wall-motion abnormalities were similarly detected by 2D and 3D speckle tracking. 2DST of triplane datasets showed similar results to those of conventional 2D datasets. 2D and 3D speckle tracking similarly detect normal and pathological wall-motion patterns. Limited image quality has a significant impact on the agreement between 3D and 2D numerical strain values.

  10. The ear: Diagnostic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vignaud, J.; Jardin, C.; Rosen, L.

    1986-01-01

    This is an English translation of volume 17-1 of Traite de radiodiagnostic and represents a reasonably complete documentation of the diseases of the temporal bone that have imaging manifestations. The book begins with chapters on embryology, anatomy and radiography anatomy; it continues with blood supply and an overview of temporal bone pathology. Subsequent chapters cover malformations, trauma, infections, tumors, postoperative changes, glomus tumors, vertebasilar insufficiency, and facial nerve canal lesions. A final chapter demonstrates and discusses magnetic resonance images of the ear and cerebellopontine angle.

  11. 2D Detectors for Particle Physics and for Imaging Applications

    CERN Document Server

    Krüger, H

    2005-01-01

    The demands on detectors for particle detection as well as for medical and astronomical X-ray imaging are continuously pushing the development of novel pixel detectors. The state of the art in pixel detector technology to date are hybrid pixel detectors in which sensor and read-out integrated circuits are processed on different substrates and connected via high density interconnect structures. While these detectors are technologically mastered such that large scale particle detectors can be and are being built, the demands for improved performance for the next generation particle detectors ask for the development of monolithic or semi-monolithic approaches. Given the fact that the demands for medical imaging are different in some key aspects, developments for these applications, which started as particle physics spin-off, are becomming rather independent. New approaches are leading to novel signal processing concepts and interconnect technologies to satisfy the need for very high dynamic range and large area ...

  12. 2D image compression using concurrent wavelet transform

    Science.gov (United States)

    Talukder, Kamrul Hasan; Harada, Koichi

    2011-10-01

    In the recent years wavelet transform (WT) has been widely used for image compression. As WT is a sequential process, much time is required to transform data. Here a new approach has been presented where the transformation process is executed concurrently. As a result the procedure runs first and the time of transformation is reduced. Multiple threads are used for row and column transformation and the communication among threads has been managed effectively. Thus, the transformation time has been reduced significantly. The proposed system provides better compression ratio and PSNR value with lower time complexity.

  13. Sampling Number Effects in 2D and Range Imaging of Range-gated Acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Seong-Ouk; Park, Seung-Kyu; Baik, Sung-Hoon; Cho, Jai-Wan; Jeong, Kyung-Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this paper, we analyzed the number effects of sampling images for making a 2D image and a range image from acquired RGI images. We analyzed the number effects of RGI images for making a 2D image and a range image using a RGI vision system. As the results, 2D image quality was not much depended on the number of sampling images but on how much well extract efficient RGI images. But, the number of RGI images was important for making a range image because range image quality was proportional to the number of RGI images. Image acquiring in a monitoring area of nuclear industry is an important function for safety inspection and preparing appropriate control plans. To overcome the non-visualization problem caused by airborne obstacle particles, vision systems should have extra-functions, such as active illumination lightening through disturbance airborne particles. One of these powerful active vision systems is a range-gated imaging system. The vision system based on the range-gated imaging system can acquire image data from raining or smoking environments. Range-gated imaging (RGI) is a direct active visualization technique using a highly sensitive image sensor and a high intensity illuminant. Currently, the range-gated imaging technique providing 2D and 3D images is one of emerging active vision technologies. The range-gated imaging system gets vision information by summing time sliced vision images. In the RGI system, a high intensity illuminant illuminates for ultra-short time and a highly sensitive image sensor is gated by ultra-short exposure time to only get the illumination light. Here, the illuminant illuminates objects by flashing strong light through airborne disturbance particles. Thus, in contrast to passive conventional vision systems, the RGI active vision technology robust for low-visibility environments.

  14. 2D IMAGE BASED SIEVING FOR PARTICLE AGGREGATE GRADATION

    Institute of Scientific and Technical Information of China (English)

    Chen Ken; John Zaniewski; Zhao Pan; Yang Ren'er

    2008-01-01

    Acquiring the size gradation for particle aggregates is a common practice in the granule related industry, and mechanical sieving or screening has been the normal method. Among many drawbacks of this conventional means, the major ones are time-consuming, labor-intensive, and being unable to provide real-time feedback for process control. In this letter, an optical sieving approach is introduced. The two-dimensional images are used to develop methods for inferring particle volume and sieving behavior for gradation purposes. And a combination of deterministic and probabilistic methods is described to predict the sieving behaviors of the particles and to construct the gradation curves for the aggregate sample. Comparison of the optical sieving with standard mechanical sieving shows good correlation.

  15. An Approach to 2D Wavelet Transform and Its Use for Image Compression

    Directory of Open Access Journals (Sweden)

    R. Vargic

    1998-12-01

    Full Text Available In this paper is constructed a new type of two-dimensional wavelet transform. Construction is based on lifting scheme. We transform 1D wavelets with symmetrical factorisation to their 2D counterparts. Comparison to existing similar 2D wavelet constructions is given. Application for image compression is given using progressive (SP1HT and classical type transform coder.

  16. Aircraft target identification based on 2D ISAR images using multiresolution analysis wavelet

    Science.gov (United States)

    Fu, Qiang; Xiao, Huaitie; Hu, Xiangjiang

    2001-09-01

    The formation of 2D ISAR images for radar target identification hold much promise for additional distinguish- ability between targets. Since an image contains important information is a wide range of scales, and this information is often independent from one scale to another, wavelet analysis provides a method of identifying the spatial frequency content of an image and the local regions within the image where those spatial frequencies exist. In this paper, a multiresolution analysis wavelet method based on 2D ISAR images was proposed for use in aircraft radar target identification under the wide band high range resolution radar background. The proposed method was performed in three steps; first, radar backscatter signals were processed in the form of 2D ISAR images, then, Mallat's wavelet algorithm was used in the decomposition of images, finally, a three layer perceptron neural net was used as classifier. The result of experiments demonstrated that the feasibility of using multiresolution analysis wavelet for target identification.

  17. Diagnostic imaging in thyrotoxicosis.

    Science.gov (United States)

    Summaria, V; Salvatori, M; Rufini, V; Mirk, P; Garganese, M C; Romani, M

    1999-01-01

    In thyrotoxicosis, imaging mainly scintigraphy, color Doppler sonography and radioiodine uptake test are used in the differential diagnosis as well as in the morphofunctional evaluation of the thyroid before and after therapy (mainly pharmacological or with radioiodine). Radioiodine uptake test differentiates high uptake thyrotoxicosis (Graves'disease, toxic nodular goiter) and low uptake thyrotoxycosis (subacute or silent thyroiditis, ectopic thyrotoxicosis, iodine-induced hyperthyroidism). In Graves'disease scintigraphy shows thyroid enlargement with intense homogeneous tracer uptake; rarely nodules with no uptake are present. On color Doppler sonography, a part from enlargement, typical findings are: diffuse structural hypoechogenicity (at times with echoic nodules), parenchymal hypervascularization ("thyroid inferno"), high systolic velocities (PSV > 70-100 cm/sec) in inferior thyroid arteries. Scintigraphy is the only method able to evidence an autonomously functioning thyroid nodule and stage it (in association to clinical findings and TSH, FT3, FT4 determination) as: toxic, non toxic (or pretoxic) and compensated, depending on whether there is inhibition of extranodular tissue. A scintigraphically "hot" nodule appears hypervascularized on color Doppler sonography (especially in the toxic or pre-toxic phase) with high PSV (> 50-70 cm/sec) in the ipsilateral inferior thyroid artery. The most reliable parameters in the evaluation of the therapeutic efficacy are: decreases in thyroid (Graves'disease) or nodular (autonomously functioning nodule) volume; decreased radioiodine uptake (Graves'disease); functional recovery of suppressed parenchyma (autonomously functioning nodule); decreased PSV in the inferior thyroid arteries.

  18. 3-D Imaging using Row--Column-Addressed 2-D Arrays with a Diverging Lens

    DEFF Research Database (Denmark)

    Bouzari, Hamed; Engholm, Mathias; Stuart, Matthias Bo

    2016-01-01

    with equipment in the price range of conventional 2-D imaging. This study proposes a delay-and-sum (DAS) beamformation scheme specific to double-curved RCA 2-D arrays and validates its focusing ability based on simulations. A synthetic aperture imaging (SAI) sequence with single element transmissions at a time...... is accurate for achieving correct time-of-flight calculations, and hence avoids geometrical distortions....

  19. A 2D and 3D electrical impedance tomography imaging using experimental data

    OpenAIRE

    Shulga, Dmitry

    2012-01-01

    In this paper model, method and results of 2D and 3D conductivity distribution imaging using experimental data are described. The 16-electrodes prototype of computer tomography system, special Matlab and Java software were used to perform imaging procedure. The developed system can be used for experimental conductivity distribution imaging and further research work.

  20. Method, Software and Aparatus for Segmenting a Series of 2D or 3D Images

    NARCIS (Netherlands)

    Noble, Nicholas M.I.; Spreeuwers, Lieuwe Jan; Breeuwer, Marcel

    2005-01-01

    he invention relates to an apparatus having means for segmenting a series of 2D or 3D images obtained by monitoring a patient's organ or other body part, wherein a first segmentation is carried out on a first image of the series of images and wherein the first segmentation is used for the subsequent

  1. Method, Software and Aparatus for Segmenting a Series of 2D or 3D Images

    NARCIS (Netherlands)

    Noble, Nicholas Michael Ian; Spreeuwers, Lieuwe Jan; Breeuwer, Marcel

    2010-01-01

    he invention relates to an apparatus having means for segmenting a series of 2D or 3D images obtained by monitoring a patient's organ or other body part, wherein a first segmentation is carried out on a first image of the series of images and wherein the first segmentation is used for the subsequent

  2. Automatic masking for robust 3D-2D image registration in image-guided spine surgery

    Science.gov (United States)

    Ketcha, M. D.; De Silva, T.; Uneri, A.; Kleinszig, G.; Vogt, S.; Wolinsky, J.-P.; Siewerdsen, J. H.

    2016-03-01

    During spinal neurosurgery, patient-specific information, planning, and annotation such as vertebral labels can be mapped from preoperative 3D CT to intraoperative 2D radiographs via image-based 3D-2D registration. Such registration has been shown to provide a potentially valuable means of decision support in target localization as well as quality assurance of the surgical product. However, robust registration can be challenged by mismatch in image content between the preoperative CT and intraoperative radiographs, arising, for example, from anatomical deformation or the presence of surgical tools within the radiograph. In this work, we develop and evaluate methods for automatically mitigating the effect of content mismatch by leveraging the surgical planning data to assign greater weight to anatomical regions known to be reliable for registration and vital to the surgical task while removing problematic regions that are highly deformable or often occluded by surgical tools. We investigated two approaches to assigning variable weight (i.e., "masking") to image content and/or the similarity metric: (1) masking the preoperative 3D CT ("volumetric masking"); and (2) masking within the 2D similarity metric calculation ("projection masking"). The accuracy of registration was evaluated in terms of projection distance error (PDE) in 61 cases selected from an IRB-approved clinical study. The best performing of the masking techniques was found to reduce the rate of gross failure (PDE > 20 mm) from 11.48% to 5.57% in this challenging retrospective data set. These approaches provided robustness to content mismatch and eliminated distinct failure modes of registration. Such improvement was gained without additional workflow and has motivated incorporation of the masking methods within a system under development for prospective clinical studies.

  3. Diagnostic imaging in bovine orthopedics.

    Science.gov (United States)

    Kofler, Johann; Geissbühler, Urs; Steiner, Adrian

    2014-03-01

    Although a radiographic unit is not standard equipment for bovine practitioners in hospital or field situations, ultrasound machines with 7.5-MHz linear transducers have been used in bovine reproduction for many years, and are eminently suitable for evaluation of orthopedic disorders. The goal of this article is to encourage veterinarians to use radiology and ultrasonography for the evaluation of bovine orthopedic disorders. These diagnostic imaging techniques improve the likelihood of a definitive diagnosis in every bovine patient but especially in highly valuable cattle, whose owners demand increasingly more diagnostic and surgical interventions that require high-level specialized techniques.

  4. Accurate positioning for head and neck cancer patients using 2D and 3D image guidance

    Science.gov (United States)

    Kang, Hyejoo; Lovelock, Dale M.; Yorke, Ellen D.; Kriminiski, Sergey; Lee, Nancy; Amols, Howard I.

    2011-01-01

    Our goal is to determine an optimized image-guided setup by comparing setup errors determined by two-dimensional (2D) and three-dimensional (3D) image guidance for head and neck cancer (HNC) patients immobilized by customized thermoplastic masks. Nine patients received weekly imaging sessions, for a total of 54, throughout treatment. Patients were first set up by matching lasers to surface marks (initial) and then translationally corrected using manual registration of orthogonal kilovoltage (kV) radiographs with DRRs (2D-2D) on bony anatomy. A kV cone beam CT (kVCBCT) was acquired and manually registered to the simulation CT using only translations (3D-3D) on the same bony anatomy to determine further translational corrections. After treatment, a second set of kVCBCT was acquired to assess intrafractional motion. Averaged over all sessions, 2D-2D registration led to translational corrections from initial setup of 3.5 ± 2.2 (range 0–8) mm. The addition of 3D-3D registration resulted in only small incremental adjustment (0.8 ± 1.5 mm). We retrospectively calculated patient setup rotation errors using an automatic rigid-body algorithm with 6 degrees of freedom (DoF) on regions of interest (ROI) of in-field bony anatomy (mainly the C2 vertebral body). Small rotations were determined for most of the imaging sessions; however, occasionally rotations > 3° were observed. The calculated intrafractional motion with automatic registration was < 3.5 mm for eight patients, and < 2° for all patients. We conclude that daily manual 2D-2D registration on radiographs reduces positioning errors for mask-immobilized HNC patients in most cases, and is easily implemented. 3D-3D registration adds little improvement over 2D-2D registration without correcting rotational errors. We also conclude that thermoplastic masks are effective for patient immobilization. PMID:21330971

  5. Multi-scale contrast enhancement of oriented features in 2D images using directional morphology

    Science.gov (United States)

    Das, Debashis; Mukhopadhyay, Susanta; Praveen, S. R. Sai

    2017-01-01

    This paper presents a multi-scale contrast enhancement scheme for improving the visual quality of directional features present in 2D gray scale images. Directional morphological filters are employed to locate and extract the scale-specific image features with different orientations which are subsequently stored in a set of feature images. The final enhanced image is constructed by weighted combination of these feature images with the original image. While construction, the feature images corresponding to progressively smaller scales are made to have higher proportion of contribution through the use of progressively larger weights. The proposed method has been formulated, implemented and executed on a set of real 2D gray scale images with oriented features. The experimental results visually establish the efficacy of the method. The proposed method has been compared with other similar methods both on subjective and objective basis and the overall performance is found to be satisfactory.

  6. 3-D Reconstruction From 2-D Radiographic Images and Its Application to Clinical Veterinary Medicine

    Science.gov (United States)

    Hamamoto, Kazuhiko; Sato, Motoyoshi

    3D imaging technique is very important and indispensable in diagnosis. The main stream of the technique is one in which 3D image is reconstructed from a set of slice images, such as X-ray CT and MRI. However, these systems require large space and high costs. On the other hand, a low cost and small size 3D imaging system is needed in clinical veterinary medicine, for example, in the case of diagnosis in X-ray car or pasture area. We propose a novel 3D imaging technique using 2-D X-ray radiographic images. This system can be realized by cheaper system than X-ray CT and enables to get 3D image in X-ray car or portable X-ray equipment. In this paper, a 3D visualization technique from 2-D radiographic images is proposed and several reconstructions are shown. These reconstructions are evaluated by veterinarians.

  7. Methods for 2-D and 3-D Endobronchial Ultrasound Image Segmentation.

    Science.gov (United States)

    Zang, Xiaonan; Bascom, Rebecca; Gilbert, Christopher; Toth, Jennifer; Higgins, William

    2016-07-01

    Endobronchial ultrasound (EBUS) is now commonly used for cancer-staging bronchoscopy. Unfortunately, EBUS is challenging to use and interpreting EBUS video sequences is difficult. Other ultrasound imaging domains, hampered by related difficulties, have benefited from computer-based image-segmentation methods. Yet, so far, no such methods have been proposed for EBUS. We propose image-segmentation methods for 2-D EBUS frames and 3-D EBUS sequences. Our 2-D method adapts the fast-marching level-set process, anisotropic diffusion, and region growing to the problem of segmenting 2-D EBUS frames. Our 3-D method builds upon the 2-D method while also incorporating the geodesic level-set process for segmenting EBUS sequences. Tests with lung-cancer patient data showed that the methods ran fully automatically for nearly 80% of test cases. For the remaining cases, the only user-interaction required was the selection of a seed point. When compared to ground-truth segmentations, the 2-D method achieved an overall Dice index = 90.0% ±4.9%, while the 3-D method achieved an overall Dice index = 83.9 ± 6.0%. In addition, the computation time (2-D, 0.070 s/frame; 3-D, 0.088 s/frame) was two orders of magnitude faster than interactive contour definition. Finally, we demonstrate the potential of the methods for EBUS localization in a multimodal image-guided bronchoscopy system.

  8. Recurrently decomposable 2-D convolvers for FPGA-based digital image processing

    OpenAIRE

    Ma' Yang, De; Liu; Bharath, AA

    2016-01-01

    Two-dimensional (2-D) convolution is a widely used operation in image processing and computer vision, characterized by intensive computation and frequent memory accesses. Previous efforts to improve the performance of field-programmable gate array (FPGA) convolvers focused on the design of buffering schemes and on minimizing the use of multipliers. A recently proposed recurrently decomposable (RD) filter design method can reduce the computational complexity of 2-D convolutions by splitting th...

  9. Development of 2D casting process CAD system based on PDF/image files

    Institute of Scientific and Technical Information of China (English)

    Tang Hongtao; Zhou Jianxin; Wang Lin; Liao Dunming; Tao Qing

    2014-01-01

    A casting process CAD is put forward to design and draw casting process. The 2D casting process CAD, most of the current systems are developed based on one certain version of the AutoCAD system. However the application of these 2D casting process CAD systems in foundry enterprises are restricted because they have several deficiencies, such as being overly dependent on the AutoCAD system, and some part files based on PDF format can not be opened directly. To overcome these deficiencies, for the first time an innovative 2D casting process CAD system based on PDF and image format file has been proposed, which breaks through the traditional research and application notion of the 2D casting process CAD system based on AutoCAD. Several key technologies of this system such as coordinate transformation, CAD interactive drawing, file storage, PDF and image format files display, and image recognition technologies were described in detail. A practical 2D CAD casting process system named HZCAD2D(PDF) was developed, which is capable of designing and drawing the casting process on the part drawing based on the PDF format directly, without spending time on drawing the part produced by AutoCAD system. Final y, taking two actual castings as examples, the casting processes were drawn using this system, demonstrating that this system can significantly shorten the cycle of casting process designing.

  10. Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image

    CERN Document Server

    Shakhakarmi, Niraj

    2012-01-01

    Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.

  11. 3D-2D Deformable Image Registration Using Feature-Based Nonuniform Meshes.

    Science.gov (United States)

    Zhong, Zichun; Guo, Xiaohu; Cai, Yiqi; Yang, Yin; Wang, Jing; Jia, Xun; Mao, Weihua

    2016-01-01

    By using prior information of planning CT images and feature-based nonuniform meshes, this paper demonstrates that volumetric images can be efficiently registered with a very small portion of 2D projection images of a Cone-Beam Computed Tomography (CBCT) scan. After a density field is computed based on the extracted feature edges from planning CT images, nonuniform tetrahedral meshes will be automatically generated to better characterize the image features according to the density field; that is, finer meshes are generated for features. The displacement vector fields (DVFs) are specified at the mesh vertices to drive the deformation of original CT images. Digitally reconstructed radiographs (DRRs) of the deformed anatomy are generated and compared with corresponding 2D projections. DVFs are optimized to minimize the objective function including differences between DRRs and projections and the regularity. To further accelerate the above 3D-2D registration, a procedure to obtain good initial deformations by deforming the volume surface to match 2D body boundary on projections has been developed. This complete method is evaluated quantitatively by using several digital phantoms and data from head and neck cancer patients. The feature-based nonuniform meshing method leads to better results than either uniform orthogonal grid or uniform tetrahedral meshes.

  12. 3D-2D Deformable Image Registration Using Feature-Based Nonuniform Meshes

    Directory of Open Access Journals (Sweden)

    Zichun Zhong

    2016-01-01

    Full Text Available By using prior information of planning CT images and feature-based nonuniform meshes, this paper demonstrates that volumetric images can be efficiently registered with a very small portion of 2D projection images of a Cone-Beam Computed Tomography (CBCT scan. After a density field is computed based on the extracted feature edges from planning CT images, nonuniform tetrahedral meshes will be automatically generated to better characterize the image features according to the density field; that is, finer meshes are generated for features. The displacement vector fields (DVFs are specified at the mesh vertices to drive the deformation of original CT images. Digitally reconstructed radiographs (DRRs of the deformed anatomy are generated and compared with corresponding 2D projections. DVFs are optimized to minimize the objective function including differences between DRRs and projections and the regularity. To further accelerate the above 3D-2D registration, a procedure to obtain good initial deformations by deforming the volume surface to match 2D body boundary on projections has been developed. This complete method is evaluated quantitatively by using several digital phantoms and data from head and neck cancer patients. The feature-based nonuniform meshing method leads to better results than either uniform orthogonal grid or uniform tetrahedral meshes.

  13. Age Estimation Based on AAM and 2D-DCT Features of Facial Images

    Directory of Open Access Journals (Sweden)

    Asuman Günay

    2015-02-01

    Full Text Available This paper proposes a novel age estimation method - Global and Local feAture based Age estiMation (GLAAM - relying on global and local features of facial images. Global features are obtained with Active Appearance Models (AAM. Local features are extracted with regional 2D-DCT (2- dimensional Discrete Cosine Transform of normalized facial images. GLAAM consists of the following modules: face normalization, global feature extraction with AAM, local feature extraction with 2D-DCT, dimensionality reduction by means of Principal Component Analysis (PCA and age estimation with multiple linear regression. Experiments have shown that GLAAM outperforms many methods previously applied to the FG-NET database.

  14. 2D digital imaging for cracks mapping of Cultural Heritage in emergency condition

    Directory of Open Access Journals (Sweden)

    Michele Russo

    2013-10-01

    Full Text Available The digital photography represents not only an immediate medium for data communication, but also an effective instrument for surveying and monitoring the architectural buildings. In this context, 2D images allow to acquire multi-scale geometrical and material data in a few time. This peculiarity makes this technique very suitable for the survey of cracks distribution in emergency condition, for example immediately after an earthquake. Referring to this specific application, the article suggests a process of 2D images acquisition, data management and representation for surveying crack distribution inside an historical building in Ferrara, Palazzo Renata di Francia, seriously damaged by the seismic events happened in May 2012.

  15. 2-D nonlinear IIR-filters for image processing - An exploratory analysis

    Science.gov (United States)

    Bauer, P. H.; Sartori, M.

    1991-01-01

    A new nonlinear IIR filter structure is introduced and its deterministic properties are analyzed. It is shown to be better suited for image processing applications than its linear shift-invariant counterpart. The new structure is obtained from causality inversion of a 2D quarterplane causal linear filter with respect to the two directions of propagation. It is demonstrated, that by using this design, a nonlinear 2D lowpass filter can be constructed, which is capable of effectively suppressing Gaussian or impulse noise without destroying important image information.

  16. 2-D nonlinear IIR-filters for image processing - An exploratory analysis

    Science.gov (United States)

    Bauer, P. H.; Sartori, M.

    1991-01-01

    A new nonlinear IIR filter structure is introduced and its deterministic properties are analyzed. It is shown to be better suited for image processing applications than its linear shift-invariant counterpart. The new structure is obtained from causality inversion of a 2D quarterplane causal linear filter with respect to the two directions of propagation. It is demonstrated, that by using this design, a nonlinear 2D lowpass filter can be constructed, which is capable of effectively suppressing Gaussian or impulse noise without destroying important image information.

  17. The segmentation of FMI image based on 2-D dyadic wavelet transform

    Science.gov (United States)

    Liu, Rui-Lin; Wu, Yue-Qi; Liu, Jian-Hua; Ma, Yong

    2005-06-01

    A key aspect in extracting quantitative information from FMI logs is to segment the FMI image to get images of pores, vugs and fractures. A segmentation method based on the dyadic wavelet transform in 2-D is introduced in this paper. The first step is to find all the edge pixels of the FMI image using the 2-D wavelet transform. The second step is to calculate a segmentation threshold based on the average value of the edge pixels. Field data processing examples show that sub-images of vugs and fractures can be correctly separated from original FMI data continuously and automatically along the depth axis. The image segmentation lays the foundation for in-situ parameter calculation.

  18. Canine Hip Dysplasia: Diagnostic Imaging.

    Science.gov (United States)

    Butler, J Ryan; Gambino, Jennifer

    2017-07-01

    Diagnostic imaging is the principal method used to screen for and diagnose hip dysplasia in the canine patient. Multiple techniques are available, each having advantages, disadvantages, and limitations. Hip-extended radiography is the most used method and is best used as a screening tool and for assessment for osteoarthritis. Distraction radiographic methods such as the PennHip method allow for improved detection of laxity and improved ability to predict future osteoarthritis development. More advanced techniques such as MRI, although expensive and not widely available, may improve patient screening and allow for improved assessment of cartilage health. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Development of a 2D temperature measurement technique for combustion diagnostics using 2-line atomic fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Johan

    2001-01-01

    The present thesis is concerned with the development and application of a novel planar laser-induced fluorescence (PLIF) technique for temperature measurements in a variety of combusting flows. Accurate measurement of temperature is an essential task in combustion diagnostics, since temperature is one of the most fundamental quantities for the characterization of combustion processes. The technique is based on two-line atomic fluorescence (TLAF) from small quantities of atomic indium (In) seeded into the fuel. It has been developed from small-scale experiments in laboratory flames to the point where practical combustion systems can be studied. The technique is conceptually simple and reveals temperature information in the post-flame regions. The viability of the technique has been tested in three extreme measurement situations: in spark ignition engine combustion, in ultra-lean combustion situations such as lean burning aero-engine concepts and, finally, in fuel-rich combustion. TLAF was successfully applied in an optical Sl engine using isooctane as fuel. The wide temperature sensitivity, 700 - 3000 K, of the technique using indium atoms allowed measurements over the entire combustion cycle in the engine to be performed. In applications in lean combustion a potential problem caused by the strong oxidation processes of indium atoms was encountered. This limits measurement times due to deposits of absorbing indium oxide on measurement windows. The seeding requirement is a disadvantage of the technique and can be a limitation in some applications. The results from experiments performed in sooting flames are very promising for thermometry measurements in such environments. Absorption by hydrocarbons and other native species was found to be negligible. Since low laser energies and low seeding concentrations could be used, the technique did not, unlike most other incoherent optical thermometry techniques, suffer interferences from LII of soot particles or LIF from PAH

  20. Recent Advancements in Microwave Imaging Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    H. Park; C.C. Chang; B.H. Deng; C.W. Domier; A.J.H. Donni; K. Kawahata; C. Liang; X.P. Liang; H.J. Lu; N.C. Luhmann, Jr.; A. Mase; H. Matsuura; E. Mazzucato; A. Miura; K. Mizuno; T. Munsat; K. and Y. Nagayama; M.J. van de Pol; J. Wang; Z.G. Xia; W-K. Zhang

    2002-03-26

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented.

  1. Automatic 2D-to-3D image conversion using 3D examples from the internet

    Science.gov (United States)

    Konrad, J.; Brown, G.; Wang, M.; Ishwar, P.; Wu, C.; Mukherjee, D.

    2012-03-01

    The availability of 3D hardware has so far outpaced the production of 3D content. Although to date many methods have been proposed to convert 2D images to 3D stereopairs, the most successful ones involve human operators and, therefore, are time-consuming and costly, while the fully-automatic ones have not yet achieved the same level of quality. This subpar performance is due to the fact that automatic methods usually rely on assumptions about the captured 3D scene that are often violated in practice. In this paper, we explore a radically different approach inspired by our work on saliency detection in images. Instead of relying on a deterministic scene model for the input 2D image, we propose to "learn" the model from a large dictionary of stereopairs, such as YouTube 3D. Our new approach is built upon a key observation and an assumption. The key observation is that among millions of stereopairs available on-line, there likely exist many stereopairs whose 3D content matches that of the 2D input (query). We assume that two stereopairs whose left images are photometrically similar are likely to have similar disparity fields. Our approach first finds a number of on-line stereopairs whose left image is a close photometric match to the 2D query and then extracts depth information from these stereopairs. Since disparities for the selected stereopairs differ due to differences in underlying image content, level of noise, distortions, etc., we combine them by using the median. We apply the resulting median disparity field to the 2D query to obtain the corresponding right image, while handling occlusions and newly-exposed areas in the usual way. We have applied our method in two scenarios. First, we used YouTube 3D videos in search of the most similar frames. Then, we repeated the experiments on a small, but carefully-selected, dictionary of stereopairs closely matching the query. This, to a degree, emulates the results one would expect from the use of an extremely large 3D

  2. Parameterising root system growth models using 2D neutron radiography images

    Science.gov (United States)

    Schnepf, Andrea; Felderer, Bernd; Vontobel, Peter; Leitner, Daniel

    2013-04-01

    Root architecture is a key factor for plant acquisition of water and nutrients from soil. In particular in view of a second green revolution where the below ground parts of agricultural crops are important, it is essential to characterise and quantify root architecture and its effect on plant resource acquisition. Mathematical models can help to understand the processes occurring in the soil-plant system, they can be used to quantify the effect of root and rhizosphere traits on resource acquisition and the response to environmental conditions. In order to do so, root architectural models are coupled with a model of water and solute transport in soil. However, dynamic root architectural models are difficult to parameterise. Novel imaging techniques such as x-ray computed tomography, neutron radiography and magnetic resonance imaging enable the in situ visualisation of plant root systems. Therefore, these images facilitate the parameterisation of dynamic root architecture models. These imaging techniques are capable of producing 3D or 2D images. Moreover, 2D images are also available in the form of hand drawings or from images of standard cameras. While full 3D imaging tools are still limited in resolutions, 2D techniques are a more accurate and less expensive option for observing roots in their environment. However, analysis of 2D images has additional difficulties compared to the 3D case, because of overlapping roots. We present a novel algorithm for the parameterisation of root system growth models based on 2D images of root system. The algorithm analyses dynamic image data. These are a series of 2D images of the root system at different points in time. Image data has already been adjusted for missing links and artefacts and segmentation was performed by applying a matched filter response. From this time series of binary 2D images, we parameterise the dynamic root architecture model in the following way: First, a morphological skeleton is derived from the binary

  3. Using 2D image composition to model and evaluate soldier camouflage in the visible wavelengths

    CSIR Research Space (South Africa)

    Duvenhage B

    2011-06-01

    Full Text Available simulation to evaluate the effectiveness of a new concept soldier camouflage pattern within a specific environment without having to print and manufacture sample uniforms. We present a 2D image composition simulator to do exactly this. If one assumes a...

  4. Estimating 3D Object Parameters from 2D Grey-Level Images

    NARCIS (Netherlands)

    Houkes, Zweitze

    2000-01-01

    This thesis describes a general framework for parameter estimation, which is suitable for computer vision applications. The approach described combines 3D modelling, animation and estimation tools to determine parameters of objects in a scene from 2D grey-level images. The animation tool predicts im

  5. A scintillating GEM detector for 2D dose imaging in hadron therapy

    NARCIS (Netherlands)

    Seravalli, E.

    2008-01-01

    The main aim of radiotherapy techniques is to deliver the dose to the target volume while sparing as much as possible the healthy tissue. Dose verifications prior the treatment of the patient are mandatory in order to guarantee high accuracy to the treatment. We have developed a 2D dose imaging sys

  6. Volumetric Ultrasound Imaging with Row-Column Addressed 2-D Arrays Using Spatial Matched Filter Beamforming

    DEFF Research Database (Denmark)

    Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann;

    2015-01-01

    For 3-D ultrasound imaging with row-column addressed 2-D arrays, the two orthogonal 1-D transmit and receive arrays are both used for one-way focusing in the lateral and elevation directions separately and since they are not in the same plane, the two-way focusing is the same as one-way focusing....

  7. A scintillating GEM detector for 2D dose imaging in hadron therapy

    NARCIS (Netherlands)

    Seravalli, E.

    2008-01-01

    The main aim of radiotherapy techniques is to deliver the dose to the target volume while sparing as much as possible the healthy tissue. Dose verifications prior the treatment of the patient are mandatory in order to guarantee high accuracy to the treatment. We have developed a 2D dose imaging

  8. Image segmentation and classification based on a 2D distributed hidden Markov model

    Science.gov (United States)

    Ma, Xiang; Schonfeld, Dan; Khokhar, Ashfaq

    2008-01-01

    In this paper, we propose a two-dimensional distributed hidden Markovmodel (2D-DHMM), where dependency of the state transition probability on any state is allowed as long as causality is preserved. The proposed 2D-DHMM model is result of a novel solution to a more general non-causal two-dimensional hidden Markovmodel (2D-HMM) that we proposed. Our proposed models can capture, for example, dependency among diagonal states, which can be critical in many image processing applications, for example, image segmentation. A new sets of basic image patterns are designed to enrich the variability of states, which in return largely improves the accuracy of state estimations and segmentation performance. We provide three algorithms for the training and classification of our proposed model. A new Expectation-Maximization (EM) algorithm suitable for estimation of the new model is derived, where a novel General Forward-Backward (GFB) algorithm is proposed for recursive estimation of the model parameters. A new conditional independent subset-state sequence structure decomposition of state sequences is proposed for the 2D Viterbi algorithm. Application to aerial image segmentation shows the superiority of our model compared to the existing models.

  9. Acoustical cross-talk in row–column addressed 2-D transducer arrays for ultrasound imaging

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann; Jensen, Jørgen Arendt; Thomsen, Erik Vilain

    2015-01-01

    The acoustical cross-talk in row–column addressed 2-D transducer arrays for volumetric ultrasound imaging is investigated. Experimental results from a 2.7 MHz, λ/2-pitch capacitive micromachined ultrasonic transducer (CMUT) array with 62 rows and 62 columns are presented and analyzed...

  10. [Rapid 2D-3D medical image registration based on CUDA].

    Science.gov (United States)

    Li, Lingzhi; Zou, Beiji

    2014-08-01

    The medical image registration between preoperative three-dimensional (3D) scan data and intraoperative two-dimensional (2D) image is a key technology in the surgical navigation. Most previous methods need to generate 2D digitally reconstructed radiographs (DRR) images from the 3D scan volume data, then use conventional image similarity function for comparison. This procedure includes a large amount of calculation and is difficult to archive real-time processing. In this paper, with using geometric feature and image density mixed characteristics, we proposed a new similarity measure function for fast 2D-3D registration of preoperative CT and intraoperative X-ray images. This algorithm is easy to implement, and the calculation process is very short, while the resulting registration accuracy can meet the clinical use. In addition, the entire calculation process is very suitable for highly parallel numerical calculation by using the algorithm based on CUDA hardware acceleration to satisfy the requirement of real-time application in surgery.

  11. The Ultrasonic Measurement of Crystallographic Orientation for Imaging Anisotropic Components with 2d Arrays

    Science.gov (United States)

    Lane, C. J. L.; Dunhill, A. K.; Drinkwater, B. W.; Wilcox, P. D.

    2011-06-01

    Single crystal components are used widely in the gas-turbine industry. However, these components are elastically anisotropic which causes difficulties when performing NDE inspections with ultrasound. Recently an ultrasonic algorithm for a 2D array has been corrected to perform the reliable volumetric inspection of single crystals. For the algorithm to be implemented the crystallographic orientation of the components must be known. This paper, therefore, develops and reviews crystallographic orientation methods using 2D ultrasonic arrays. The methods under examination are based on the anisotropic propagation of surface and bulk waves and an image-based orientation method is also considered.

  12. Research on 2D representation method of wireless Micro-Ball endoscopic images.

    Science.gov (United States)

    Wang, Dan; Xie, Xiang; Li, Guolin; Gu, Yingke; Yin, Zheng; Wang, Zhihua

    2012-01-01

    Nowadays the interpretation of the images acquired by wireless endoscopy system is a tedious job for doctors. A viable solution is to construct a map, which is the 2D representation of gastrointestinal (GI) tract to reduce the redundancy of images and improve the understandability of them. The work reported in this paper addresses the problem of the 2D representation of GI tract based on a new wireless Micro-Ball endoscopy system with multiple image sensors. This paper firstly models the problem of constructing the map, and then discusses mainly on the issues of perspective distortion correction, image preprocessing and image registration, which lie in the whole problem. The perspective distortion correction algorithm is realized based on attitude angles, while the image registration is based on phase correlation method (PCM) and scale invariant feature transform (SIFT) combined with particular image preprocessing methods. Based on R channels of images, the algorithm can deal with 26.3% to 100% of image registration when the ratio of overlap varies from 25% to 80%. The performance and effectiveness of the algorithms are verified by experiments.

  13. A positioning QA procedure for 2D/2D (kV/MV) and 3D/3D (CT/CBCT) image matching for radiotherapy patient setup.

    Science.gov (United States)

    Guan, Huaiqun; Hammoud, Rabih; Yin, Fang-Fang

    2009-10-06

    A positioning QA procedure for Varian's 2D/2D (kV/MV) and 3D/3D (planCT/CBCT) matching was developed. The procedure was to check: (1) the coincidence of on-board imager (OBI), portal imager (PI), and cone beam CT (CBCT)'s isocenters (digital graticules) to a linac's isocenter (to a pre-specified accuracy); (2) that the positioning difference detected by 2D/2D (kV/MV) and 3D/3D(planCT/CBCT) matching can be reliably transferred to couch motion. A cube phantom with a 2 mm metal ball (bb) at the center was used. The bb was used to define the isocenter. Two additional bbs were placed on two phantom surfaces in order to define a spatial location of 1.5 cm anterior, 1.5 cm inferior, and 1.5 cm right from the isocenter. An axial scan of the phantom was acquired from a multislice CT simulator. The phantom was set at the linac's isocenter (lasers); either AP MV/R Lat kV images or CBCT images were taken for 2D/2D or 3D/3D matching, respectively. For 2D/2D, the accuracy of each device's isocenter was obtained by checking the distance between the central bb and the digital graticule. Then the central bb in orthogonal DRRs was manually moved to overlay to the off-axis bbs in kV/MV images. For 3D/3D, CBCT was first matched to planCT to check the isocenter difference between the two CTs. Manual shifts were then made by moving CBCT such that the point defined by the two off-axis bbs overlay to the central bb in planCT. (PlanCT can not be moved in the current version of OBI1.4.) The manual shifts were then applied to remotely move the couch. The room laser was used to check the accuracy of the couch movement. For Trilogy (or Ix-21) linacs, the coincidence of imager and linac's isocenter was better than 1 mm (or 1.5 mm). The couch shift accuracy was better than 2 mm.

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

    Science.gov (United States)

    He, Jiaze; Yuan, Fuh-Gwo

    2016-10-01

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

  15. A fast convolution-based methodology to simulate 2-D/3-D cardiac ultrasound images.

    Science.gov (United States)

    Gao, Hang; Choi, Hon Fai; Claus, Piet; Boonen, Steven; Jaecques, Siegfried; Van Lenthe, G Harry; Van der Perre, Georges; Lauriks, Walter; D'hooge, Jan

    2009-02-01

    This paper describes a fast convolution-based methodology for simulating ultrasound images in a 2-D/3-D sector format as typically used in cardiac ultrasound. The conventional convolution model is based on the assumption of a space-invariant point spread function (PSF) and typically results in linear images. These characteristics are not representative for cardiac data sets. The spatial impulse response method (IRM) has excellent accuracy in the linear domain; however, calculation time can become an issue when scatterer numbers become significant and when 3-D volumetric data sets need to be computed. As a solution to these problems, the current manuscript proposes a new convolution-based methodology in which the data sets are produced by reducing the conventional 2-D/3-D convolution model to multiple 1-D convolutions (one for each image line). As an example, simulated 2-D/3-D phantom images are presented along with their gray scale histogram statistics. In addition, the computation time is recorded and contrasted to a commonly used implementation of IRM (Field II). It is shown that COLE can produce anatomically plausible images with local Rayleigh statistics but at improved calculation time (1200 times faster than the reference method).

  16. Simultaneous 3D–2D image registration and C-arm calibration: Application to endovascular image-guided interventions

    Energy Technology Data Exchange (ETDEWEB)

    Mitrović, Uroš [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000, Slovenia and Cosylab, Control System Laboratory, Teslova ulica 30, Ljubljana 1000 (Slovenia); Pernuš, Franjo [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000 (Slovenia); Likar, Boštjan; Špiclin, Žiga, E-mail: ziga.spiclin@fe.uni-lj.si [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000, Slovenia and Sensum, Computer Vision Systems, Tehnološki Park 21, Ljubljana 1000 (Slovenia)

    2015-11-15

    Purpose: Three-dimensional to two-dimensional (3D–2D) image registration is a key to fusion and simultaneous visualization of valuable information contained in 3D pre-interventional and 2D intra-interventional images with the final goal of image guidance of a procedure. In this paper, the authors focus on 3D–2D image registration within the context of intracranial endovascular image-guided interventions (EIGIs), where the 3D and 2D images are generally acquired with the same C-arm system. The accuracy and robustness of any 3D–2D registration method, to be used in a clinical setting, is influenced by (1) the method itself, (2) uncertainty of initial pose of the 3D image from which registration starts, (3) uncertainty of C-arm’s geometry and pose, and (4) the number of 2D intra-interventional images used for registration, which is generally one and at most two. The study of these influences requires rigorous and objective validation of any 3D–2D registration method against a highly accurate reference or “gold standard” registration, performed on clinical image datasets acquired in the context of the intervention. Methods: The registration process is split into two sequential, i.e., initial and final, registration stages. The initial stage is either machine-based or template matching. The latter aims to reduce possibly large in-plane translation errors by matching a projection of the 3D vessel model and 2D image. In the final registration stage, four state-of-the-art intrinsic image-based 3D–2D registration methods, which involve simultaneous refinement of rigid-body and C-arm parameters, are evaluated. For objective validation, the authors acquired an image database of 15 patients undergoing cerebral EIGI, for which accurate gold standard registrations were established by fiducial marker coregistration. Results: Based on target registration error, the obtained success rates of 3D to a single 2D image registration after initial machine-based and

  17. 2D sparse array transducer optimization for 3D ultrasound imaging

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Hoon; Park, Kwan Kyu [Dept. of Mechanical Convergence Engineering, Hanyang University, Seoul (Korea, Republic of)

    2016-12-15

    A 3D ultrasound image is desired in many medical examinations. However, the implementation of a 2D array, which is needed for a 3D image, is challenging with respect to fabrication, interconnection and cabling. A 2D sparse array, which needs fewer elements than a dense array, is a realistic way to achieve 3D images. Because the number of ways the elements can be placed in an array is extremely large, a method for optimizing the array configuration is needed. Previous research placed the target point far from the transducer array, making it impossible to optimize the array in the operating range. In our study, we focused on optimizing a 2D sparse array transducer for 3D imaging by using a simulated annealing method. We compared the far-field optimization method with the near-field optimization method by analyzing a point-spread function (PSF). The resolution of the optimized sparse array is comparable to that of the dense array.

  18. Detecting myocardial ischemia with 2-D CVIB imaging method--an in vivo animal experiment study

    Institute of Scientific and Technical Information of China (English)

    JIANG Yong; BAI Jing; YING Kui; CHENG Kezheng; YU Can

    2004-01-01

    A 2-D cyclic variation of integrated backscatter (CVIB) imaging method was established for detecting myocardial ischemia. To demonstrate the feasibility and validity of this method, animal experiments were conducted. Acute myocardial ischemia was induced by occluding left anterior descending coronary artery in 10 anesthetized open-chest dogs. While scanning the normal hearts and the ischemic hearts with a B scanner, digital radiofrequency data were acquired by a real-time acquisition system in synchronism. The offline analysis to the radio-frequency signal with the 2-D CVIB imaging method was performed to verify the consistency between the imaging result and the design of the experiment. In addition, 4 dogs in experiment were treated with the heart pacemaker in order to investigate the influence of changing in heart rate on the detection of ischemic myocardium with the proposed method. The experimental result showed that the 2-D CVIB imaging method succeeded in detecting the ischemic myocardium and is a new non-invasive way for the cardiologists to both quantitatively and visually evaluate the contractile performance of the myocardium.

  19. 2D and 3D optical diagnostic techniques applied to Madonna dei Fusi by Leonardo da Vinci

    Science.gov (United States)

    Fontana, R.; Gambino, M. C.; Greco, M.; Marras, L.; Materazzi, M.; Pampaloni, E.; Pelagotti, A.; Pezzati, L.; Poggi, P.; Sanapo, C.

    2005-06-01

    3D measurement and modelling have been traditionally applied to statues, buildings, archeological sites or similar large structures, but rarely to paintings. Recently, however, 3D measurements have been performed successfully also on easel paintings, allowing to detect and document the painting's surface. We used 3D models to integrate the results of various 2D imaging techniques on a common reference frame. These applications show how the 3D shape information, complemented with 2D colour maps as well as with other types of sensory data, provide the most interesting information. The 3D data acquisition was carried out by means of two devices: a high-resolution laser micro-profilometer, composed of a commercial distance meter mounted on a scanning device, and a laser-line scanner. The 2D data acquisitions were carried out using a scanning device for simultaneous RGB colour imaging and IR reflectography, and a UV fluorescence multispectral image acquisition system. We present here the results of the techniques described, applied to the analysis of an important painting of the Italian Reinassance: `Madonna dei Fusi', attributed to Leonardo da Vinci.

  20. Localization of significant 3D objects in 2D images for generic vision tasks

    Science.gov (United States)

    Mokhtari, Marielle; Bergevin, Robert

    1995-10-01

    Computer vision experiments are not very often linked to practical applications but rather deal with typical laboratory experiments under controlled conditions. For instance, most object recognition experiments are based on specific models used under limitative constraints. Our work proposes a general framework for rapidly locating significant 3D objects in 2D static images of medium to high complexity, as a prerequisite step to recognition and interpretation when no a priori knowledge of the contents of the scene is assumed. In this paper, a definition of generic objects is proposed, covering the structures that are implied in the image. Under this framework, it must be possible to locate generic objects and assign a significance figure to each one from any image fed to the system. The most significant structure in a given image becomes the focus of interest of the system determining subsequent tasks (like subsequent robot moves, image acquisitions and processing). A survey of existing strategies for locating 3D objects in 2D images is first presented and our approach is defined relative to these strategies. Perceptual grouping paradigms leading to the structural organization of the components of an image are at the core of our approach.

  1. a New 2d Otsu for Water Extraction from SAR Image

    Science.gov (United States)

    Guo, Y.; Zhang, J.

    2017-09-01

    SAR image segmentation is a crucial step that heavily influences the performance of image interpretation. The texture factor to replace the neighborhood mean dimension in the traditional Otsu method is proposed in this work, aiming at the problem that the SAR image has unique characteristics and the original 2D Otsu method only considers the pixel neighborhood mean information. In this paper, TerraSAR image with the single band and single polarization is used to water extraction. Firstly, the semantic function is used to analyze the structural characteristics of the sample image to determine the optimal parameters of the texture information extraction. Then, calculate the textural measures such as contrast, entropy, homogeneity, mean and second moment based on gray level co-occurrence matrix(GLCM) method. The results are compared with the artificially marked images and the results of the original 2D Otsu.The experimental results achieve higher objective values, which shows the proposed algorithm using texture factor has a high practical value for SAR Image water segmentation.

  2. 3D Modeling of Transformer Substation Based on Mapping and 2D Images

    Directory of Open Access Journals (Sweden)

    Lei Sun

    2016-01-01

    Full Text Available A new method for building 3D models of transformer substation based on mapping and 2D images is proposed in this paper. This method segments objects of equipment in 2D images by using k-means algorithm in determining the cluster centers dynamically to segment different shapes and then extracts feature parameters from the divided objects by using FFT and retrieves the similar objects from 3D databases and then builds 3D models by computing the mapping data. The method proposed in this paper can avoid the complex data collection and big workload by using 3D laser scanner. The example analysis shows the method can build coarse 3D models efficiently which can meet the requirements for hazardous area classification and constructions representations of transformer substation.

  3. Image Pretreatment Tools II: Normalization Techniques for 2-DE and 2-D DIGE.

    Science.gov (United States)

    Robotti, Elisa; Marengo, Emilio; Quasso, Fabio

    2016-01-01

    Gel electrophoresis is usually applied to identify different protein expression profiles in biological samples (e.g., control vs. pathological, control vs. treated). Information about the effect to be investigated (a pathology, a drug, a ripening effect, etc.) is however generally confounded with experimental variability that is quite large in 2-DE and may arise from small variations in the sample preparation, reagents, sample loading, electrophoretic conditions, staining and image acquisition. Obtaining valid quantitative estimates of protein abundances in each map, before the differential analysis, is therefore fundamental to provide robust candidate biomarkers. Normalization procedures are applied to reduce experimental noise and make the images comparable, improving the accuracy of differential analysis. Certainly, they may deeply influence the final results, and to this respect they have to be applied with care. Here, the most widespread normalization procedures are described both for what regards the applications to 2-DE and 2D Difference Gel-electrophoresis (2-D DIGE) maps.

  4. The EOS 2D/3D X-ray imaging system

    OpenAIRE

    Faria, Rita; McKenna, Claire; Wade, Rosalind Fay; Yang, Huiqin; Woolacott, Nerys; Sculpher, Mark

    2013-01-01

    OBJECTIVES: To evaluate the cost-effectiveness of the EOS® 2D/3D X-ray imaging system compared with standard X-ray for the diagnosis and monitoring of orthopaedic conditions. MATERIALS AND METHODS: A decision analytic model was developed to quantify the long-term costs and health outcomes, expressed as quality-adjusted life years (QALYs) from the UK health service perspective. Input parameters were obtained from medical literature, previously developed cancer models and expert advice. Thresho...

  5. Image restoration using 2D autoregressive texture model and structure curve construction

    Science.gov (United States)

    Voronin, V. V.; Marchuk, V. I.; Petrosov, S. P.; Svirin, I.; Agaian, S.; Egiazarian, K.

    2015-05-01

    In this paper an image inpainting approach based on the construction of a composite curve for the restoration of the edges of objects in an image using the concepts of parametric and geometric continuity is presented. It is shown that this approach allows to restore the curved edges and provide more flexibility for curve design in damaged image by interpolating the boundaries of objects by cubic splines. After edge restoration stage, a texture restoration using 2D autoregressive texture model is carried out. The image intensity is locally modeled by a first spatial autoregressive model with support in a strongly causal prediction region on the plane. Model parameters are estimated by Yule-Walker method. Several examples considered in this paper show the effectiveness of the proposed approach for large objects removal as well as recovery of small regions on several test images.

  6. SADDLE-POINT BASED SEPARATION OF TOUCHED OBJECTS IN 2-D IMAGE

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In many image analysis and processing problems, discriminating the size and shape of each individual object in an aggregate pile projected in an image is an important practice. It is relatively easy to distinguish these features among the objects already separated from each other. The problems will be undoubtedly more complex and of greater challenge if the objects are touched or/and overlapped. This letter presents an algorithm that can be used to separate the touches and overlaps existing in the objects within a 2-D image. The approach is first to convert the gray-scale image to its corresponding binary one and then to the 3-D topographic one using the erosion operations. A template (or mask) is engineered to search the topographic surface for the saddle point, from which the segmenting orientation is determined followed by the desired separating operation. The algorithm is tested on a real image and the running result is adequately satisfying and encouraging.

  7. Night vision image fusion for target detection with improved 2D maximum entropy segmentation

    Science.gov (United States)

    Bai, Lian-fa; Liu, Ying-bin; Yue, Jiang; Zhang, Yi

    2013-08-01

    Infrared and LLL image are used for night vision target detection. In allusion to the characteristics of night vision imaging and lack of traditional detection algorithm for segmentation and extraction of targets, we propose a method of infrared and LLL image fusion for target detection with improved 2D maximum entropy segmentation. Firstly, two-dimensional histogram was improved by gray level and maximum gray level in weighted area, weights were selected to calculate the maximum entropy for infrared and LLL image segmentation by using the histogram. Compared with the traditional maximum entropy segmentation, the algorithm had significant effect in target detection, and the functions of background suppression and target extraction. And then, the validity of multi-dimensional characteristics AND operation on the infrared and LLL image feature level fusion for target detection is verified. Experimental results show that detection algorithm has a relatively good effect and application in target detection and multiple targets detection in complex background.

  8. A new efficient 2D combined with 3D CAD system for solitary pulmonary nodule detection in CT images

    Directory of Open Access Journals (Sweden)

    Xing Li

    2011-06-01

    Full Text Available Lung cancer has become one of the leading causes of death in the world. Clear evidence shows that early discovery, early diagnosis and early treatment of lung cancer can significantly increase the chance of survival for patients. Lung Computer-Aided Diagnosis (CAD is a potential method to accomplish a range of quantitative tasks such as early cancer and disease detection. Many computer-aided diagnosis (CAD methods, including 2D and 3D approaches, have been proposed for solitary pulmonary nodules (SPNs. However, the detection and diagnosis of SPNs remain challenging in many clinical circumstances. One goal of this work is to develop a two-stage approach that combines the simplicity of 2D and the accuracy of 3D methods. The experimental results show statistically significant differences between the diagnostic accuracy of 2D and 3Dmethods. The results also show that with a very minor drop in diagnostic performance the two-stage approach can significantly reduce the number of nodules needed to be processed by the 3D method, streamlining the computational demand. Finally, all malignant nodules were detected and a very low false-positive detection rate was achieved. The automated extraction of the lung in CT images is the most crucial step in a computer-aided diagnosis (CAD system. In this paper we describe a method, consisting of appropriate techniques, for the automated identification of the pulmonary volume. The performance is evaluated as a fully automated computerized method for the detection of lung nodules in computed tomography (CT scans in the identification of lung cancers that may be missed during visual interpretation.

  9. 2D matrix based indexing with color spectral histogram for efficient image retrieval

    Institute of Scientific and Technical Information of China (English)

    Maruthamuthu Ramasamy; John Sanjeev Kumar Athisayam

    2016-01-01

    A novel content based image retrieval (CBIR) algorithm using relevant feedback is presented. The proposed framework has three major contributions: a novel feature descriptor cal ed color spectral histogram (CSH) to measure the similarity between images; two-dimensional matrix based indexing approach pro-posed for short-term learning (STL);and long-term learning (LTL). In general, image similarities are measured from feature repre-sentation which includes color quantization, texture, color, shape and edges. However, CSH can describe the image feature only with the histogram. Typical y the image retrieval process starts by finding the similarity between the query image and the images in the database; the major computation involved here is that the selection of top ranking images requires a sorting algorithm to be employed at least with the lower bound of O(n log n). A 2D ma-trix based indexing of images can enormously reduce the search time in STL. The same structure is used for LTL with an aim to reduce the amount of log to be maintained. The performance of the proposed framework is analyzed and compared with the exist-ing approaches, the quantified results indicates that the proposed feature descriptor is more effectual than the existing feature de-scriptors that were original y developed for CBIR. In terms of STL, the proposed 2D matrix based indexing minimizes the computation effort for retrieving similar images and for LTL, the proposed algo-rithm takes minimum log information than the existing approaches.

  10. 2-D minimum fuzzy entropy method of image thresholding based on genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new image thresholding method is introduced, which is based on 2-D histgram and minimizing the measures of fuzziness of an input image. A new definition of fuzzy membership function is proposed, it denotes the characteristic relationship between the gray level of each pixel and the average value of its neighborhood. When the threshold is not located at the obvious and deep valley ofthe histgram, genetic algorithm is devoted to the problem of selecting the appropriate threshold value. The experimental results indicate that the proposed method has good performance.

  11. JetCurry: Modeling 3D geometry of AGN jets from 2D images

    Science.gov (United States)

    Kosak, Katie; Li, KunYang; Avachat, Sayali S.; Perlman, Eric S.

    2017-02-01

    Written in Python, JetCurry models the 3D geometry of jets from 2-D images. JetCurry requires NumPy and SciPy and incorporates emcee (ascl:1303.002) and AstroPy (ascl:1304.002), and optionally uses VPython. From a defined initial part of the jet that serves as a reference point, JetCurry finds the position of highest flux within a bin of data in the image matrix and fits along the x axis for the general location of the bends in the jet. A spline fitting is used to smooth out the resulted jet stream.

  12. Wide area 2D/3D imaging development, analysis and applications

    CERN Document Server

    Langmann, Benjamin

    2014-01-01

    Imaging technology is an important research area and it is widely utilized in a growing number of disciplines ranging from gaming, robotics and automation to medicine. In the last decade 3D imaging became popular mainly driven by the introduction of novel 3D cameras and measuring devices. These cameras are usually limited to indoor scenes with relatively low distances. Benjamin Langmann introduces medium and long-range 2D/3D cameras to overcome these limitations. He reports measurement results for these devices and studies their characteristic behavior. In order to facilitate the application o

  13. 2D image classification for 3D anatomy localization: employing deep convolutional neural networks

    Science.gov (United States)

    de Vos, Bob D.; Wolterink, Jelmer M.; de Jong, Pim A.; Viergever, Max A.; Išgum, Ivana

    2016-03-01

    Localization of anatomical regions of interest (ROIs) is a preprocessing step in many medical image analysis tasks. While trivial for humans, it is complex for automatic methods. Classic machine learning approaches require the challenge of hand crafting features to describe differences between ROIs and background. Deep convolutional neural networks (CNNs) alleviate this by automatically finding hierarchical feature representations from raw images. We employ this trait to detect anatomical ROIs in 2D image slices in order to localize them in 3D. In 100 low-dose non-contrast enhanced non-ECG synchronized screening chest CT scans, a reference standard was defined by manually delineating rectangular bounding boxes around three anatomical ROIs -- heart, aortic arch, and descending aorta. Every anatomical ROI was automatically identified using a combination of three CNNs, each analyzing one orthogonal image plane. While single CNNs predicted presence or absence of a specific ROI in the given plane, the combination of their results provided a 3D bounding box around it. Classification performance of each CNN, expressed in area under the receiver operating characteristic curve, was >=0.988. Additionally, the performance of ROI localization was evaluated. Median Dice scores for automatically determined bounding boxes around the heart, aortic arch, and descending aorta were 0.89, 0.70, and 0.85 respectively. The results demonstrate that accurate automatic 3D localization of anatomical structures by CNN-based 2D image classification is feasible.

  14. Image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing

    Science.gov (United States)

    Zhou, Nanrun; Pan, Shumin; Cheng, Shan; Zhou, Zhihong

    2016-08-01

    Most image encryption algorithms based on low-dimensional chaos systems bear security risks and suffer encryption data expansion when adopting nonlinear transformation directly. To overcome these weaknesses and reduce the possible transmission burden, an efficient image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing is proposed. The original image is measured by the measurement matrices in two directions to achieve compression and encryption simultaneously, and then the resulting image is re-encrypted by the cycle shift operation controlled by a hyper-chaotic system. Cycle shift operation can change the values of the pixels efficiently. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys distribution simultaneously as a nonlinear encryption system. Simulation results verify the validity and the reliability of the proposed algorithm with acceptable compression and security performance.

  15. 2D dose distribution images of a hybrid low field MRI-γ detector

    Science.gov (United States)

    Abril, A.; Agulles-Pedrós, L.

    2016-07-01

    The proposed hybrid system is a combination of a low field MRI and dosimetric gel as a γ detector. The readout system is based on the polymerization process induced by the gel radiation. A gel dose map is obtained which represents the functional part of hybrid image alongside with the anatomical MRI one. Both images should be taken while the patient with a radiopharmaceutical is located inside the MRI system with a gel detector matrix. A relevant aspect of this proposal is that the dosimetric gel has never been used to acquire medical images. The results presented show the interaction of the 99mTc source with the dosimetric gel simulated in Geant4. The purpose was to obtain the planar γ 2D-image. The different source configurations are studied to explore the ability of the gel as radiation detector through the following parameters; resolution, shape definition and radio-pharmaceutical concentration.

  16. A combined sensor for simultaneous high resolution 2-D imaging of oxygen and trace metals fluxes

    DEFF Research Database (Denmark)

    Stahl, Henrik; Warnken, Kent W.; Sochaczewski, Lukasz

    2012-01-01

    A new sandwich sensor, consisting of an O-2 planar optode overlain by a thin (90 mu m) DGT layer is presented. This sensor can simultaneously resolve 2-D O-2 dynamics and trace metal fluxes in benthic substrates at a high spatial resolution. The DGT layer accumulates metals on a small particle size...... (0.2 mu m) chelating resin and records the locally induced trace metal flux during the deployment, whereas the planar optode resolves the O-2 dynamic in near real time at the same location in the sediment. Despite its ultrathin composition, the DGT layer has high carrying capacity for trace metals...... with no saturation problems during application to typical coastal-or contaminated sediments. Combined with laser ablation, accumulated metal fluxes could be resolved at a resolution of similar to 200 mu m, whereas the O-2 images had a resolution of similar to 100 mu m. A 2-D diffusion-reaction model showed...

  17. Volumetric synthetic aperture imaging with a piezoelectric 2D row-column probe

    Science.gov (United States)

    Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann; Beers, Christopher; Lei, Anders; Stuart, Matthias Bo; Nikolov, Svetoslav Ivanov; Thomsen, Erik Vilain; Jensen, Jørgen Arendt

    2016-04-01

    The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using 2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-house prototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row-column addressed transducer array. Utilizing single element transmit events, a volume rate of 90 Hz down to 14 cm deep is achieved. Data are obtained using the experimental ultrasound scanner SARUS with a 70 MHz sampling frequency and beamformed using a delay-and-sum (DAS) approach. A signal-to-noise ratio of up to 32 dB is measured on the beamformed images of a tissue mimicking phantom with attenuation of 0.5 dB cm-1 MHz-1, from the surface of the probe to the penetration depth of 300λ. Measured lateral resolution as Full-Width-at-Half-Maximum (FWHM) is between 4λ and 10λ for 18% to 65% of the penetration depth from the surface of the probe. The averaged contrast is 13 dB for the same range. The imaging performance assessment results may represent a reference guide for possible applications of such an array in different medical fields.

  18. Designing of sparse 2D arrays for Lamb wave imaging using coarray concept

    Science.gov (United States)

    Ambroziński, Łukasz; Stepinski, Tadeusz; Uhl, Tadeusz

    2015-03-01

    2D ultrasonic arrays have considerable application potential in Lamb wave based SHM systems, since they enable equivocal damage imaging and even in some cases wave-mode selection. Recently, it has been shown that the 2D arrays can be used in SHM applications in a synthetic focusing (SF) mode, which is much more effective than the classical phase array mode commonly used in NDT. The SF mode assumes a single element excitation of subsequent transmitters and off-line processing the acquired data. In the simplest implementation of the technique, only single multiplexed input and output channels are required, which results in significant hardware simplification. Application of the SF mode for 2D arrays creates additional degrees of freedom during the design of the array topology, which complicates the array design process, however, it enables sparse array designs with performance similar to that of the fully populated dense arrays. In this paper we present the coarray concept to facilitate synthesis process of an array's aperture used in the multistatic synthetic focusing approach in Lamb waves-based imaging systems. In the coherent imaging, performed in the transmit/receive mode, the sum coarray is a morphological convolution of the transmit/receive sub-arrays. It can be calculated as the set of sums of the individual sub-arrays' elements locations. The coarray framework will be presented here using a an example of a star-shaped array. The approach will be discussed in terms of beampatterns of the resulting imaging systems. Both simulated and experimental results will be included.

  19. Designing of sparse 2D arrays for Lamb wave imaging using coarray concept

    Energy Technology Data Exchange (ETDEWEB)

    Ambroziński, Łukasz, E-mail: ambrozin@agh.edu.pl; Stepinski, Tadeusz, E-mail: ambrozin@agh.edu.pl; Uhl, Tadeusz, E-mail: ambrozin@agh.edu.pl [AGH University of Science and technology, al. Mickiewicza 30, 30-059 Krakow (Poland)

    2015-03-31

    2D ultrasonic arrays have considerable application potential in Lamb wave based SHM systems, since they enable equivocal damage imaging and even in some cases wave-mode selection. Recently, it has been shown that the 2D arrays can be used in SHM applications in a synthetic focusing (SF) mode, which is much more effective than the classical phase array mode commonly used in NDT. The SF mode assumes a single element excitation of subsequent transmitters and off-line processing the acquired data. In the simplest implementation of the technique, only single multiplexed input and output channels are required, which results in significant hardware simplification. Application of the SF mode for 2D arrays creates additional degrees of freedom during the design of the array topology, which complicates the array design process, however, it enables sparse array designs with performance similar to that of the fully populated dense arrays. In this paper we present the coarray concept to facilitate synthesis process of an array’s aperture used in the multistatic synthetic focusing approach in Lamb waves-based imaging systems. In the coherent imaging, performed in the transmit/receive mode, the sum coarray is a morphological convolution of the transmit/receive sub-arrays. It can be calculated as the set of sums of the individual sub-arrays’ elements locations. The coarray framework will be presented here using a an example of a star-shaped array. The approach will be discussed in terms of beampatterns of the resulting imaging systems. Both simulated and experimental results will be included.

  20. Adaptive optofluidic lens(es) for switchable 2D and 3D imaging

    Science.gov (United States)

    Huang, Hanyang; Wei, Kang; Zhao, Yi

    2016-03-01

    The stereoscopic image is often captured using dual cameras arranged side-by-side and optical path switching systems such as two separate solid lenses or biprism/mirrors. The miniaturization of the overall size of current stereoscopic devices down to several millimeters is at a sacrifice of further device size shrinkage. The limited light entry worsens the final image resolution and brightness. It is known that optofluidics offer good re-configurability for imaging systems. Leveraging this technique, we report a reconfigurable optofluidic system whose optical layout can be swapped between a singlet lens with 10 mm in diameter and a pair of binocular lenses with each lens of 3 mm in diameter for switchable two-dimensional (2D) and three-dimensional (3D) imaging. The singlet and the binoculars share the same optical path and the same imaging sensor. The singlet acquires a 3D image with better resolution and brightness, while the binoculars capture stereoscopic image pairs for 3D vision and depth perception. The focusing power tuning capability of the singlet and the binoculars enable image acquisition at varied object planes by adjusting the hydrostatic pressure across the lens membrane. The vari-focal singlet and binoculars thus work interchangeably and complementarily. The device is thus expected to have applications in robotic vision, stereoscopy, laparoendoscopy and miniaturized zoom lens system.

  1. An Approach to Face Recognition of 2-D Images Using Eigen Faces and PCA

    Directory of Open Access Journals (Sweden)

    Annapurna Mishra

    2012-05-01

    Full Text Available Face detection is to find any face in a given image. Face recognition is a two-dimension problem used fordetecting faces. The information contained in a face can be analysed automatically by this system likeidentity, gender, expression, age, race and pose. Normally face detection is done for a single image but itcan also be extended for video stream. As the face images are normally upright, they can be described by asmall set of 2-D characteristics views. Here the face images are projected to a feature space or face spaceto encode the variation between the known face images. The projected feature space or the face space canbe defined as ‘eigenfaces’ and can be formed by eigenvectors of the face image set. The above process canbe used to recognize a new face in unsupervised manner. This paper introduces an algorithm which is usedfor effective face recognition. It takes into consideration not only the face extraction but also themathematical calculations which enable us to bring the image into a simple and technical form. It can alsobe implemented in real-time using data acquisition hardware and software interface with the facerecognition systems. Face recognition can be applied to various domains including security systems,personal identification, image and film processing and human computer interaction.

  2. An Approach to Face Recognition of 2-D Images Using Eigen Faces and PCA

    Directory of Open Access Journals (Sweden)

    Annapurna Mishra

    2012-04-01

    Full Text Available Face detection is to find any face in a given image. Face recognition is a two-dimension problem used for detecting faces. The information contained in a face can be analysed automatically by this system like identity, gender, expression, age, race and pose. Normally face detection is done for a single image but it can also be extended for video stream. As the face images are normally upright, they can be described by a small set of 2-D characteristics views. Here the face images are projected to a feature space or face space to encode the variation between the known face images. The projected feature space or the face space can be defined as ‘eigenfaces’ and can be formed by eigenvectors of the face image set. The above process can be used to recognize a new face in unsupervised manner. This paper introduces an algorithm which is used for effective face recognition. It takes into consideration not only the face extraction but also the mathematical calculations which enable us to bring the image into a simple and technical form. It can also be implemented in real-time using data acquisition hardware and software interface with the face recognition systems. Face recognition can be applied to various domains including security systems, personal identification, image and film processing and human computer interaction.

  3. 3D Materials image segmentation by 2D propagation: a graph-cut approach considering homomorphism.

    Science.gov (United States)

    Waggoner, Jarrell; Zhou, Youjie; Simmons, Jeff; De Graef, Marc; Wang, Song

    2013-12-01

    Segmentation propagation, similar to tracking, is the problem of transferring a segmentation of an image to a neighboring image in a sequence. This problem is of particular importance to materials science, where the accurate segmentation of a series of 2D serial-sectioned images of multiple, contiguous 3D structures has important applications. Such structures may have distinct shape, appearance, and topology, which can be considered to improve segmentation accuracy. For example, some materials images may have structures with a specific shape or appearance in each serial section slice, which only changes minimally from slice to slice, and some materials may exhibit specific inter-structure topology that constrains their neighboring relations. Some of these properties have been individually incorporated to segment specific materials images in prior work. In this paper, we develop a propagation framework for materials image segmentation where each propagation is formulated as an optimal labeling problem that can be efficiently solved using the graph-cut algorithm. Our framework makes three key contributions: 1) a homomorphic propagation approach, which considers the consistency of region adjacency in the propagation; 2) incorporation of shape and appearance consistency in the propagation; and 3) a local non-homomorphism strategy to handle newly appearing and disappearing substructures during this propagation. To show the effectiveness of our framework, we conduct experiments on various 3D materials images, and compare the performance against several existing image segmentation methods.

  4. A simple model for 2D image upconversion of incoherent light

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2011-01-01

    We present a simple theoretical model for 2 dimensional (2-D) image up-conversion of incoherent light. While image upconversion has been known for more than 40 years, the technology has been hindered by very low conversion quantum efficiency (~10-7). We show that our implementation compared...... to previous work can result in a feasible system: Using intracavity upconversion and Quasi Phase Matching (QPM) nonlinear materials provide increased conversion efficiency. Using a QPM crystal and choosing the wavelengths so the first order term in the phasematch wavelength acceptance vanishes, results...... in very large wavelength acceptance. This work describes how the bandwidth acceptance can be predicted and designed. This gives promise of a new way to make infrared imaging devices with tunable spectral sensitivity....

  5. GPU accelerated generation of digitally reconstructed radiographs for 2-D/3-D image registration.

    Science.gov (United States)

    Dorgham, Osama M; Laycock, Stephen D; Fisher, Mark H

    2012-09-01

    Recent advances in programming languages for graphics processing units (GPUs) provide developers with a convenient way of implementing applications which can be executed on the CPU and GPU interchangeably. GPUs are becoming relatively cheap, powerful, and widely available hardware components, which can be used to perform intensive calculations. The last decade of hardware performance developments shows that GPU-based computation is progressing significantly faster than CPU-based computation, particularly if one considers the execution of highly parallelisable algorithms. Future predictions illustrate that this trend is likely to continue. In this paper, we introduce a way of accelerating 2-D/3-D image registration by developing a hybrid system which executes on the CPU and utilizes the GPU for parallelizing the generation of digitally reconstructed radiographs (DRRs). Based on the advancements of the GPU over the CPU, it is timely to exploit the benefits of many-core GPU technology by developing algorithms for DRR generation. Although some previous work has investigated the rendering of DRRs using the GPU, this paper investigates approximations which reduce the computational overhead while still maintaining a quality consistent with that needed for 2-D/3-D registration with sufficient accuracy to be clinically acceptable in certain applications of radiation oncology. Furthermore, by comparing implementations of 2-D/3-D registration on the CPU and GPU, we investigate current performance and propose an optimal framework for PC implementations addressing the rigid registration problem. Using this framework, we are able to render DRR images from a 256×256×133 CT volume in ~24 ms using an NVidia GeForce 8800 GTX and in ~2 ms using NVidia GeForce GTX 580. In addition to applications requiring fast automatic patient setup, these levels of performance suggest image-guided radiation therapy at video frame rates is technically feasible using relatively low cost PC

  6. Automatic 2D/3D Vessel Enhancement in Multiple Modality Images Using a Weighted Symmetry Filter.

    Science.gov (United States)

    Zhao, Yitian; Zhao, Yitian; Zheng, Yalin; Liu, Yonghuai; Zhao, Yifan; Luo, Lingling; Yang, Siyuan; Na, Tong; Wang, Yongtian; Liu, Jiang

    2017-09-25

    Automated detection of vascular structures is of great importance in understanding the mechanism, diagnosis and treatment of many vascular pathologies. However, automatic vascular detection continues to be an open issue because of difficulties posed by multiple factors such as poor contrast, inhomogeneous backgrounds, anatomical variations, and the presence of noise during image acquisition. In this paper, we propose a novel 2D/3D symmetry filter to tackle these challenging issues for enhancing vessels from different imaging modalities. The proposed filter not only considers local phase features by using a quadrature filter to distinguish between lines and edges, but also uses the weighted geometric mean of the blurred and shifted responses of the quadrature filter, which allows more tolerance of vessels with irregular appearance. As a result, this filter shows a strong response to the vascular features under typical imaging conditions. Results based on 8 publicly available datasets (six 2D datasets, one 3D dataset and one 3D synthetic dataset) demonstrate its superior performance to other state-ofthe- art methods.

  7. A mm-Wave 2D Ultra-Wideband Imaging Radar for Breast Cancer Detection

    Directory of Open Access Journals (Sweden)

    Stefano Moscato

    2013-01-01

    Full Text Available This paper presents the preliminary design of a mm-wave ultra-wideband (UWB radar for breast cancer detection. A mass screening of women for breast cancer is essential, as the early diagnosis of the tumour allows best treatment outcomes. A mm-wave UWB radar could be an innovative solution to achieve the high imaging resolution required without risks for the patient. The 20–40 GHz frequency band used in the system proposed in this work guarantees high cross/range resolution performances. The developed preliminary architecture employs two monomodal truncated double-ridge waveguides that act as antennas; these radiators are shifted by microstep actuators to form a synthetic linear aperture. The minimum antenna-to-antenna distance achievable, the width of the synthetic aperture, and the minimum frequency step determine the performance of the 2D imaging system. Measures are performed with a mm-wave vector network analyzer driven by an automatic routine, which controls also the antennas shifts. The scattering matrix is then calibrated and the delay-multiply-and-sum (DMAS algorithm is applied to elaborate a high-resolution 2D image of the targets. Experimental results show that 3 mm cross and 8 mm range resolutions were achieved, which is in line with theoretical expectations and promising for future developments.

  8. A 2D eye gaze estimation system with low-resolution webcam images

    Directory of Open Access Journals (Sweden)

    Kim Jin

    2011-01-01

    Full Text Available Abstract In this article, a low-cost system for 2D eye gaze estimation with low-resolution webcam images is presented. Two algorithms are proposed for this purpose, one for the eye-ball detection with stable approximate pupil-center and the other one for the eye movements' direction detection. Eyeball is detected using deformable angular integral search by minimum intensity (DAISMI algorithm. Deformable template-based 2D gaze estimation (DTBGE algorithm is employed as a noise filter for deciding the stable movement decisions. While DTBGE employs binary images, DAISMI employs gray-scale images. Right and left eye estimates are evaluated separately. DAISMI finds the stable approximate pupil-center location by calculating the mass-center of eyeball border vertices to be employed for initial deformable template alignment. DTBGE starts running with initial alignment and updates the template alignment with resulting eye movements and eyeball size frame by frame. The horizontal and vertical deviation of eye movements through eyeball size is considered as if it is directly proportional with the deviation of cursor movements in a certain screen size and resolution. The core advantage of the system is that it does not employ the real pupil-center as a reference point for gaze estimation which is more reliable against corneal reflection. Visual angle accuracy is used for the evaluation and benchmarking of the system. Effectiveness of the proposed system is presented and experimental results are shown.

  9. 2D Iterative MAP Detection: Principles and Applications in Image Restoration

    Directory of Open Access Journals (Sweden)

    D. Kekrt

    2014-06-01

    Full Text Available The paper provides a theoretical framework for the two-dimensional iterative maximum a posteriori detection. This generalization is based on the concept of detection algorithms BCJR and SOVA, i.e., the classical (one-dimensional iterative detectors used in telecommunication applications. We generalize the one-dimensional detection problem considering the spatial ISI kernel as a two-dimensional finite state machine (2D FSM representing a network of the spatially concatenated elements. The cellular structure topology defines the design of the 2D Iterative decoding network, where each cell is a general combination-marginalization statistical element (SISO module exchanging discrete probability density functions (information metrics with neighboring cells. In this paper, we statistically analyse the performance of various topologies with respect to their application in the field of image restoration. The iterative detection algorithm was applied on the task of binarization of images taken from a CCD camera. The reconstruction includes suppression of the defocus caused by the lens, CCD sensor noise suppression and interpolation (demosaicing. The simulations prove that the algorithm provides satisfactory results even in the case of an input image that is under-sampled due to the Bayer mask.

  10. Acoustical cross-talk in row–column addressed 2-D transducer arrays for ultrasound imaging

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann; Jensen, Jørgen Arendt; Thomsen, Erik Vilain

    2015-01-01

    The acoustical cross-talk in row–column addressed 2-D transducer arrays for volumetric ultrasound imaging is investigated. Experimental results from a 2.7 MHz, λ/2-pitch capacitive micromachined ultrasonic transducer (CMUT) array with 62 rows and 62 columns are presented and analyzed...... in the frequency-wavenumber domain. The sources of cross-talk are identified and predicted theoretically. The nearest neighbor cross-talk is 23.9±3.7 dB when the array is used as a 1-D array with the rows functioning as both transmitters and receivers. In the row–column configuration, with the columns transmitting...

  11. Application of Enhanced-2D-CWT in Topographic Images for Mapping Landslide Risk Areas

    CERN Document Server

    Valenzuela, V V Vermehren; de Oliveira, H M

    2015-01-01

    There has been lately a number of catastrophic events of landslides and mudslides in the mountainous region of Rio de Janeiro, Brazil. Those were caused by intense rain in localities where there was unplanned occupation of slopes of hills and mountains. Thus, it became imperative creating an inventory of landslide risk areas in densely populated cities. This work presents a way of demarcating risk areas by using the bidimensional Continuous Wavelet Transform (2D-CWT) applied to high resolution topographic images of the mountainous region of Rio de Janeiro.

  12. 2D aperture synthesis for Lamb wave imaging using co-arrays

    Science.gov (United States)

    Ambrozinski, Lukasz; Stepinski, Tadeusz; Uhl, Tadeusz

    2014-03-01

    2D ultrasonic arrays in Lamb wave based SHM systems can operate in the phased array (PA) or synthetic focusing (SF) mode. In the real-time PA approach, multiple electronically delayed signals excite transmitting elements to form the desired wave-front, whereas receiving elements are used to sense scattered waves. Due to that, the PA mode requires multi channeled hardware and multiple excitations at numerous azimuths to scan the inspected region of interest. To the contrary, the SF mode, assumes a single element excitation of subsequent transmitters and off-line processing of the acquired data. In the simplest implementation of the SF technique, a single multiplexed input and output channels are required, which results in significant hardware simplification. Performance of a 2D imaging array depends on many parameters, such as, its topology, number of its transducers and their spacing in terms of wavelength as well as the type of weighting function (apodization). Moreover, it is possible to use sparse arrays, which means that not all array elements are used for transmitting and/ or receiving. In this paper the co-array concept is applied to facilitate the synthesis process of an array's aperture used in the multistatic synthetic focusing approach in Lamb waves-based imaging systems. In the coherent imaging, performed in the transmit/receive mode, the sum co-array is a morphological convolution of the transmit/receive sub-arrays. It can be calculated as the set of sums of the individual elements' locations in the sub-arrays used for imaging. The coarray framework will be presented here using two different array topologies, aID uniform linear array and a cross-shaped array that will result in a square coarray. The approach will be discussed in terms of array patterns and beam patterns of the resulting imaging systems. Both, theoretical and experimental results will be given.

  13. Pattern recognition using invariants defined from higher order spectra: 2-D image inputs.

    Science.gov (United States)

    Chandran, V; Carswell, B; Boashash, B; Elgar, S

    1997-01-01

    A new algorithm for extracting features from images for object recognition is described. The algorithm uses higher order spectra to provide desirable invariance properties, to provide noise immunity, and to incorporate nonlinearity into the feature extraction procedure thereby allowing the use of simple classifiers. An image can be reduced to a set of 1D functions via the Radon transform, or alternatively, the Fourier transform of each 1D projection can be obtained from a radial slice of the 2D Fourier transform of the image according to the Fourier slice theorem. A triple product of Fourier coefficients, referred to as the deterministic bispectrum, is computed for each 1D function and is integrated along radial lines in bifrequency space. Phases of the integrated bispectra are shown to be translation- and scale-invariant. Rotation invariance is achieved by a regrouping of these invariants at a constant radius followed by a second stage of invariant extraction. Rotation invariance is thus converted to translation invariance in the second step. Results using synthetic and actual images show that isolated, compact clusters are formed in feature space. These clusters are linearly separable, indicating that the nonlinearity required in the mapping from the input space to the classification space is incorporated well into the feature extraction stage. The use of higher order spectra results in good noise immunity, as verified with synthetic and real images. Classification of images using the higher order spectra-based algorithm compares favorably to classification using the method of moment invariants.

  14. Radiogenomic imaging-linking diagnostic imaging and molecular diagnostics

    Institute of Scientific and Technical Information of China (English)

    Mathias; Goyen

    2014-01-01

    Radiogenomic imaging refers to the correlation between cancer imaging features and gene expression and is one of the most promising areas within science and medicine. High-throughput biological techniques have reshaped the perspective of biomedical research allowing for fast and efficient assessment of the entire molecular topography of a cell’s physiology providing new insights into human cancers. The use of non-invasive imaging tools for gene expression profiling of solid tumors could serve as a means for linking specific imaging features with specific gene expression patterns thereby allowing for more accurate diagnosis and prognosis and obviating the need for high-risk invasive biopsy procedures. This review focuses on the medical imaging part as one of the main drivers for the development of radiogenomic imaging.

  15. 2-D IMAGE-BASED VOLUMETRIC MODELING FOR PARTICLE OF RANDOM SHAPE

    Institute of Scientific and Technical Information of China (English)

    Chen Ken; Larry E. Banta; Jiang Gangyi

    2006-01-01

    In this paper, an approach to predicting randomly-shaped particle volume based on its twoDimensional (2-D) digital image is explored. Conversion of gray-scale image of the particles to its binary counterpart is first performed using backlighting technique. The silhouette of particle is thus obtained, and consequently, informative features such as particle area, centroid and shape-related descriptors are collected. Several dimensionless parameters are defined, and used as regressor variables in a multiple linear regression model to predict particle volume. Regressor coefficients are found by fitting to a randomly selected sample of 501 particles ranging in size from 4.75mm to 25mm. The model testing experiment is conducted against a different aggregate sample of the similar statistical properties, the errors of the model-predicted volume of the batch is within ±2%.

  16. Novel 2D-sequential color code system employing Image Sensor Communications for Optical Wireless Communications

    Directory of Open Access Journals (Sweden)

    Trang Nguyen

    2016-06-01

    Full Text Available The IEEE 802.15.7r1 Optical Wireless Communications Task Group (TG7r1, also known as the revision of the IEEE 802.15.7 Visible Light Communication standard targeting the commercial usage of visible light communication systems, is of interest in this paper. The paper is mainly concerned with Image Sensor Communications (ISC of TG7r1; however, the major challenge facing ISC, as addressed in the Technical Consideration Document (TCD of TG7r1, is Image Sensor Compatibility among the variety of different commercial cameras on the market. One of the most challenging but interesting compatibility requirements is the need to support the verified presence of frame rate variation. This paper proposes a novel design for 2D-sequential color code. Compared to a QR-code-based sequential transmission, the proposed design of 2D-sequential code can overcome the above challenge that it is compatible with different frame rate variations and different shutter operations, and has the ability to mitigate the rolling effect as well as the rotating effect while effectively minimizing transmission overhead. Practical implementations are demonstrated and a performance comparison is presented.

  17. Plane-wave transverse oscillation for high-frame-rate 2-D vector flow imaging.

    Science.gov (United States)

    Lenge, Matteo; Ramalli, Alessandro; Tortoli, Piero; Cachard, Christian; Liebgott, Hervé

    2015-12-01

    Transverse oscillation (TO) methods introduce oscillations in the pulse-echo field (PEF) along the direction transverse to the ultrasound propagation direction. This may be exploited to extend flow investigations toward multidimensional estimates. In this paper, the TOs are coupled with the transmission of plane waves (PWs) to reconstruct high-framerate RF images with bidirectional oscillations in the pulse-echo field. Such RF images are then processed by a 2-D phase-based displacement estimator to produce 2-D vector flow maps at thousands of frames per second. First, the capability of generating TOs after PW transmissions was thoroughly investigated by varying the lateral wavelength, the burst length, and the transmission frequency. Over the entire region of interest, the generated lateral wavelengths, compared with the designed ones, presented bias and standard deviation of -3.3 ± 5.7% and 10.6 ± 7.4% in simulations and experiments, respectively. The performance of the ultrafast vector flow mapping method was also assessed by evaluating the differences between the estimated velocities and the expected ones. Both simulations and experiments show overall biases lower than 20% when varying the beam-to-flow angle, the peak velocity, and the depth of interest. In vivo applications of the method on the common carotid and the brachial arteries are also presented.

  18. Groundwater exploration using 2D Resistivity Imaging in Pagoh, Johor, Malaysia

    Science.gov (United States)

    Kadri, Muhammad; Nawawi, M. N. M.

    2010-12-01

    Groundwater is a very important component of water resources in nature. Since the demand of groundwater increases with population growth, it is necessary to explore groundwater more intensively. In Malaysia only less than 2% of the present water used is developed from groundwater. In order to determine the existence of usable groundwater for irrigation and drinking purposes in Pagoh, 2D resistivity imaging technique was utilized. The 2-D resistivity imaging technique utilized the Wenner—Schlumberger electrode array configuration because this array is moderately sensitive to both horizontal and vertical structures. Three lines were surveyed for groundwater delineation purpose The length for each survey lines are 400 meters. At Pagoh, the survey site shows the existence of groundwater. It is indicated by the resistivity values about 10-100 ohm-m. The maximum depth of investigation survey is 77 meters. In general the results show that the subsurface is made up of alluvium and clay and the high resistivity values of more than 1000 ohm-m near the surface is due laterite and the end of the depth can be interpreted as mixture of weathered material or bedrock.

  19. Diagnostic performance of 3D TSE MRI versus 2D TSE MRI of the knee at 1.5 T, with prompt arthroscopic correlation, in the detection of meniscal and cruciate ligament tears

    Directory of Open Access Journals (Sweden)

    Francisco Abaeté Chagas-Neto

    2016-04-01

    Full Text Available Abstract Objective: To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE magnetic resonance imaging (MRI technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods: Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results: For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively and specificity (80% and 85%, respectively. For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively and specificity (68% and 71%, respectively. In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively and specificity (82% and 92%, respectively. There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion: The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition.

  20. Diagnostic performance of 3D TSE MRI versus 2D TSE MRI of the knee at 1.5 T, with prompt arthroscopic correlation, in the detection of meniscal and cruciate ligament tears*

    Science.gov (United States)

    Chagas-Neto, Francisco Abaeté; Nogueira-Barbosa, Marcello Henrique; Lorenzato, Mário Müller; Salim, Rodrigo; Kfuri-Junior, Maurício; Crema, Michel Daoud

    2016-01-01

    Objective To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE) magnetic resonance imaging (MRI) technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE) protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively) and specificity (80% and 85%, respectively). For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively) and specificity (68% and 71%, respectively). In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively) and specificity (82% and 92%, respectively). There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition. PMID:27141127

  1. Three-dimensional imaging of acetabular dysplasia: diagnostic value and impact on surgical type classification

    Energy Technology Data Exchange (ETDEWEB)

    Smet, Maria-Helena E-mail: marleen.smet@uz.kuleuven.ac.be; Marchal, Guy J.; Baert, Albert L.; Hoe, Lieven van; Cleynenbreugel, Johan van; Daniels, Hans; Molenaers, Guy; Moens, Pierre; Fabry, Guy

    2000-04-01

    Objective: To investigate the diagnostic value and the impact on surgical type classification of three-dimensional (3D) images for pre-surgical evaluation of dysplastic hips. Materials and methods: Three children with a different surgical type of hip dysplasia were investigated with helical computed tomography. For each patient, two-dimensional (2D) images, 3D, and a stereolithographic model of the dysplastic hip were generated. In two separate sessions, 40 medical observers independently analyzed the 2D images (session 1), the 2D and 3D images (session 2), and tried to identify the corresponding stereolithographic hip model. The influence of both image presentation (2D versus 3D images) and observer (degree of experience, radiologist versus orthopedic surgeon) were statistically analyzed. The SL model choice reflected the impact on surgical type classification. Results: Image presentation was a significant factor whereas the individual observer was not. Three-dimensional images scored significantly better than 2D images (P=0.0003). Three-dimensional imaging increased the correct surgical type classification by 35%. Conclusion: Three-dimensional images significantly improve the pre-surgical diagnostic assessment and surgical type classification of dysplastic hips.

  2. Rotationally symmetric triangulation sensor with integrated object imaging using only one 2D detector

    Science.gov (United States)

    Eckstein, Johannes; Lei, Wang; Becker, Jonathan; Jun, Gao; Ott, Peter

    2006-04-01

    In this paper a distance measurement sensor is introduced, equipped with two integrated optical systems, the first one for rotationally symmetric triangulation and the second one for imaging the object while using only one 2D detector for both purposes. Rotationally symmetric triangulation, introduced in [1], eliminates some disadvantages of classical triangulation sensors, especially at steps or strong curvatures of the object, wherefore the measurement result depends not any longer on the angular orientation of the sensor. This is achieved by imaging the scattered light from an illuminated object point to a centered and sharp ring on a low cost area detector. The diameter of the ring is proportional to the distance of the object. The optical system consists of two off axis aspheric reflecting surfaces. This system allows for integrating a second optical system in order to capture images of the object at the same 2D detector. A mock-up was realized for the first time which consists of the reflecting optics for triangulation manufactured by diamond turning. A commercially available appropriate small lens system for imaging was mechanically integrated in the reflecting optics. Alternatively, some designs of retrofocus lens system for larger field of views were investigated. The optical designs allow overlying the image of the object and the ring for distance measurement in the same plane. In this plane a CCD detector is mounted, centered to the optical axis for both channels. A fast algorithm for the evaluation of the ring is implemented. The characteristics, i.e. the ring diameter versus object distance shows very linear behavior. For illumination of the object point for distance measurement, the beam of a red laser diode system is reflected by a wavelength bandpath filter on the axis of the optical system in. Additionally, the surface of the object is illuminated by LED's in the green spectrum. The LED's are located on the outside rim of the reflecting optics. The

  3. Method for 3D Object Reconstruction Using Several Portion of 2D Images from the Different Aspects Acquired with Image Scopes Included in the Fiber Retractor

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2012-12-01

    Full Text Available Method for 3D object reconstruction using several portions of 2D images from the different aspects which are acquired with image scopes included in the fiber retractor is proposed. Experimental results show a great possibilityfor reconstruction of acceptable quality of 3D object on the computer with several imageswhich are viewed from the different aspects of 2D images.

  4. On the use of steady-state signal equations for 2D TrueFISP imaging.

    Science.gov (United States)

    Coolen, Bram F; Heijman, Edwin; Nicolay, Klaas; Strijkers, Gustav J

    2009-07-01

    To explain the signal behavior in 2D-TrueFISP imaging, a slice excitation profile should be considered that describes a variation of effective flip angles and magnetization phases after excitation. These parameters can be incorporated into steady-state equations to predict the final signal within a pixel. The use of steady-state equations assumes that excitation occurs instantaneously, although in reality this is a nonlinear process. In addition, often the flip angle variation within the slice excitation profile is solely considered when using steady-state equations, while TrueFISP is especially known for its sensitivity to phase variations. The purpose of this study was therefore to evaluate the precision of steady-state equations in calculating signal intensities in 2D TrueFISP imaging. To that end, steady-state slice profiles and corresponding signal intensities were calculated as function of flip angle, RF phase advance and pulse shape. More complex Bloch simulations were considered as a gold standard, which described every excitation within the sequence until steady state was reached. They were used to analyze two different methods based on steady-state equations. In addition, measurements on phantoms were done with corresponding imaging parameters. Although the Bloch simulations described the steady-state slice profile formation better than methods based on steady-state equations, the latter performed well in predicting the steady-state signal resulting from it. In certain cases the phase variation within the slice excitation profile did not even have to be taken into account.

  5. Singular value decomposition-based 2D image reconstruction for computed tomography.

    Science.gov (United States)

    Liu, Rui; He, Lu; Luo, Yan; Yu, Hengyong

    2017-01-01

    Singular value decomposition (SVD)-based 2D image reconstruction methods are developed and evaluated for a broad class of inverse problems for which there are no analytical solutions. The proposed methods are fast and accurate for reconstructing images in a non-iterative fashion. The multi-resolution strategy is adopted to reduce the size of the system matrix to reconstruct large images using limited memory capacity. A modified high-contrast Shepp-Logan phantom, a low-contrast FORBILD head phantom, and a physical phantom are employed to evaluate the proposed methods with different system configurations. The results show that the SVD methods can accurately reconstruct images from standard scan and interior scan projections and that they outperform other benchmark methods. The general SVD method outperforms the other SVD methods. The truncated SVD and Tikhonov regularized SVD methods accurately reconstruct a region-of-interest (ROI) from an internal scan with a known sub-region inside the ROI. Furthermore, the SVD methods are much faster and more flexible than the benchmark algorithms, especially in the ROI reconstructions in our experiments.

  6. Embedded morphological dilation coding for 2D and 3D images

    Science.gov (United States)

    Lazzaroni, Fabio; Signoroni, Alberto; Leonardi, Riccardo

    2002-01-01

    Current wavelet-based image coders obtain high performance thanks to the identification and the exploitation of the statistical properties of natural images in the transformed domain. Zerotree-based algorithms, as Embedded Zerotree Wavelets (EZW) and Set Partitioning In Hierarchical Trees (SPIHT), offer high Rate-Distortion (RD) coding performance and low computational complexity by exploiting statistical dependencies among insignificant coefficients on hierarchical subband structures. Another possible approach tries to predict the clusters of significant coefficients by means of some form of morphological dilation. An example of a morphology-based coder is the Significance-Linked Connected Component Analysis (SLCCA) that has shown performance which are comparable to the zerotree-based coders but is not embedded. A new embedded bit-plane coder is proposed here based on morphological dilation of significant coefficients and context based arithmetic coding. The algorithm is able to exploit both intra-band and inter-band statistical dependencies among wavelet significant coefficients. Moreover, the same approach is used both for two and three-dimensional wavelet-based image compression. Finally we the algorithms are tested on some 2D images and on a medical volume, by comparing the RD results to those obtained with the state-of-the-art wavelet-based coders.

  7. Interobserver, intraobserver and intrapatient reliability scores of myocardial strain imaging with 2-d echocardiography in patients treated with anthracyclines.

    NARCIS (Netherlands)

    Mavinkurve-Groothuis, A.M.C.; Weijers, G.; Groot-Loonen, J.J.; Pourier, M.S.; Feuth, A.B.; Korte, C.L. de; Hoogerbrugge, P.M.; Kapusta, L.

    2009-01-01

    Myocardial strain imaging with 2-D echocardiography is a relatively new noninvasive method to assess myocardial deformation. To determine the interobserver, intraobserver and intrapatient reliability scores, we evaluated myocardial strain measurements of 10 asymptomatic survivors of childhood cancer

  8. Curvilinear 3-D Imaging Using Row--Column-Addressed 2-D Arrays with a Diverging Lens: Feasibility Study

    DEFF Research Database (Denmark)

    Bouzari, Hamed; Engholm, Mathias; Beers, Christopher

    2017-01-01

    Constructing a double-curved row–columnaddressed (RCA) 2-D array or applying a diverging lens over the flat RCA 2-D array can extend the imaging field-of-view (FOV) to a curvilinear volume without increasing the aperture size, which is necessary for applications such as abdominal and cardiac imag...... of this study demonstrate that the proposed beamforming approach is accurate for achieving correct time-of-flight calculations, and hence avoids geometrical distortions....

  9. Transmission Error and Compression Robustness of 2D Chaotic Map Image Encryption Schemes

    Directory of Open Access Journals (Sweden)

    Michael Gschwandtner

    2007-11-01

    Full Text Available This paper analyzes the robustness properties of 2D chaotic map image encryption schemes. We investigate the behavior of such block ciphers under different channel error types and find the transmission error robustness to be highly dependent on on the type of error occurring and to be very different as compared to the effects when using traditional block ciphers like AES. Additionally, chaotic-mixing-based encryption schemes are shown to be robust to lossy compression as long as the security requirements are not too high. This property facilitates the application of these ciphers in scenarios where lossy compression is applied to encrypted material, which is impossible in case traditional ciphers should be employed. If high security is required chaotic mixing loses its robustness to transmission errors and compression, still the lower computational demand may be an argument in favor of chaotic mixing as compared to traditional ciphers when visual data is to be encrypted.

  10. Transmission Error and Compression Robustness of 2D Chaotic Map Image Encryption Schemes

    Directory of Open Access Journals (Sweden)

    Gschwandtner Michael

    2007-01-01

    Full Text Available This paper analyzes the robustness properties of 2D chaotic map image encryption schemes. We investigate the behavior of such block ciphers under different channel error types and find the transmission error robustness to be highly dependent on on the type of error occurring and to be very different as compared to the effects when using traditional block ciphers like AES. Additionally, chaotic-mixing-based encryption schemes are shown to be robust to lossy compression as long as the security requirements are not too high. This property facilitates the application of these ciphers in scenarios where lossy compression is applied to encrypted material, which is impossible in case traditional ciphers should be employed. If high security is required chaotic mixing loses its robustness to transmission errors and compression, still the lower computational demand may be an argument in favor of chaotic mixing as compared to traditional ciphers when visual data is to be encrypted.

  11. Contributions in compression of 3D medical images and 2D images; Contributions en compression d'images medicales 3D et d'images naturelles 2D

    Energy Technology Data Exchange (ETDEWEB)

    Gaudeau, Y

    2006-12-15

    The huge amounts of volumetric data generated by current medical imaging techniques in the context of an increasing demand for long term archiving solutions, as well as the rapid development of distant radiology make the use of compression inevitable. Indeed, if the medical community has sided until now with compression without losses, most of applications suffer from compression ratios which are too low with this kind of compression. In this context, compression with acceptable losses could be the most appropriate answer. So, we propose a new loss coding scheme based on 3D (3 dimensional) Wavelet Transform and Dead Zone Lattice Vector Quantization 3D (DZLVQ) for medical images. Our algorithm has been evaluated on several computerized tomography (CT) and magnetic resonance image volumes. The main contribution of this work is the design of a multidimensional dead zone which enables to take into account correlations between neighbouring elementary volumes. At high compression ratios, we show that it can out-perform visually and numerically the best existing methods. These promising results are confirmed on head CT by two medical patricians. The second contribution of this document assesses the effect with-loss image compression on CAD (Computer-Aided Decision) detection performance of solid lung nodules. This work on 120 significant lungs images shows that detection did not suffer until 48:1 compression and still was robust at 96:1. The last contribution consists in the complexity reduction of our compression scheme. The first allocation dedicated to 2D DZLVQ uses an exponential of the rate-distortion (R-D) functions. The second allocation for 2D and 3D medical images is based on block statistical model to estimate the R-D curves. These R-D models are based on the joint distribution of wavelet vectors using a multidimensional mixture of generalized Gaussian (MMGG) densities. (author)

  12. Flow and Transport of Radionuclides in the Rhizosphere: Imaging and Measurements in a 2D System

    Science.gov (United States)

    Pales, Ashley; Darnault, Christophe; Li, Biting; Clifford, Heather; Montgomery, Dawn; Moysey, Stephen; Powell, Brian; DeVol, Tim; Erdmann, Bryan; Edayilam, Nimisha; Tharayil, Nishanth; Dogan, Mine; Martinez, Nicole

    2017-04-01

    This research aims to build upon past 2D tank light transmission methods to quantify real-time flow in unsaturated porous media, understand how exudates effect unstable flow patterns, and understand radionuclide mobility and dispersion in the subsurface. A 2D tank light transmission method was created using a transparent flow through tank coupled with a random rainfall simulator; a commercial LED light and a CMOS DSLR Nikon D5500 camera were used to capture the real-time flow images. The images were broken down from RGB into HVI and analyzed in Matlab to produce quantifiable data about finger formation and water saturation distribution. Radionuclide locations were determined via handheld gamma scanner. Water saturation along the vertical and horizontal profile (Matlab) was used to quantify the finger more objectively than by eye assessment alone. The changes in finger formation and speed of propagation between the control rain water (0.01M NaCl) and the solutions containing plant exudates illustrates that the plant exudates increased the wettability (mobility) of water moving through unsaturated porous media. This understanding of plant exudates effect on unsaturated flow is important for works studying how plants, their roots and exudates, may affect the mobility of radionuclides in unsaturated porous media. As there is an increase in exudate concentration, the mobility of the radionuclides due to changing flow pattern and available water content in porous media may be improved causing more dispersion in the porous media and intake into the plant. Changes in plant root exudation impact the distribution and density of radionuclides in the rhizosphere and vadose zone.

  13. Uncooled Terahertz real-time imaging 2D arrays developed at LETI: present status and perspectives

    Science.gov (United States)

    Simoens, François; Meilhan, Jérôme; Dussopt, Laurent; Nicolas, Jean-Alain; Monnier, Nicolas; Sicard, Gilles; Siligaris, Alexandre; Hiberty, Bruno

    2017-05-01

    As for other imaging sensor markets, whatever is the technology, the commercial spread of terahertz (THz) cameras has to fulfil simultaneously the criteria of high sensitivity and low cost and SWAP (size, weight and power). Monolithic silicon-based 2D sensors integrated in uncooled THz real-time cameras are good candidates to meet these requirements. Over the past decade, LETI has been studying and developing such arrays with two complimentary technological approaches, i.e. antenna-coupled silicon bolometers and CMOS Field Effect Transistors (FET), both being compatible to standard silicon microelectronics processes. LETI has leveraged its know-how in thermal infrared bolometer sensors in developing a proprietary architecture for THz sensing. High technological maturity has been achieved as illustrated by the demonstration of fast scanning of large field of view and the recent birth of a commercial camera. In the FET-based THz field, recent works have been focused on innovative CMOS read-out-integrated circuit designs. The studied architectures take advantage of the large pixel pitch to enhance the flexibility and the sensitivity: an embedded in-pixel configurable signal processing chain dramatically reduces the noise. Video sequences at 100 frames per second using our 31x31 pixels 2D Focal Plane Arrays (FPA) have been achieved. The authors describe the present status of these developments and perspectives of performance evolutions are discussed. Several experimental imaging tests are also presented in order to illustrate the capabilities of these arrays to address industrial applications such as non-destructive testing (NDT), security or quality control of food.

  14. Interference filter spectral imaging of twilight O+(2P-2D emission

    Directory of Open Access Journals (Sweden)

    R. H. Wiens

    Full Text Available A spectral imager specifically designed to measure the O+(2P-2D emission in the thermosphere during twilight has been constructed and tested in Toronto (43.8°N, 79.3°W, and found to show promise for long-term and campaign-mode operations. A modification of the mesopause oxygen rotational temperature imager (MORTI, it consists basically of a narrow-band interference filter (0.14 nm bandwidth to separate wavelengths as a function of off-axis angle, a lens to focus the spectrum into a series of concentric rings, and a focal plane array (CCD to record the spectral images in digital form. The instrument was built with two fields of view, one for the zenith and one for 20° above the horizon, movable to track the azimuth of the Sun, in order to provide appropriate data for inversion. Data gathered during June 1991 provided measurements of the column-integrated emission rate with a precision of about 3%. An atomic oxygen profile was deduced that showed good agreement with that predicted by the MSIS-90 model atmosphere. Geomagnetically induced variations of the O+ lines, calcium spectra resulting from meteor showers, and OH nightglow were also observed.

  15. The neutron imaging diagnostic at NIF (invited).

    Science.gov (United States)

    Merrill, F E; Bower, D; Buckles, R; Clark, D D; Danly, C R; Drury, O B; Dzenitis, J M; Fatherley, V E; Fittinghoff, D N; Gallegos, R; Grim, G P; Guler, N; Loomis, E N; Lutz, S; Malone, R M; Martinson, D D; Mares, D; Morley, D J; Morgan, G L; Oertel, J A; Tregillis, I L; Volegov, P L; Weiss, P B; Wilde, C H; Wilson, D C

    2012-10-01

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  16. Absorption and scattering 2-D volcano images from numerically calculated space-weighting functions

    Science.gov (United States)

    Del Pezzo, Edoardo; Ibañez, Jesus; Prudencio, Janire; Bianco, Francesca; De Siena, Luca

    2016-08-01

    Short-period small magnitude seismograms mainly comprise scattered waves in the form of coda waves (the tail part of the seismogram, starting after S waves and ending when the noise prevails), spanning more than 70 per cent of the whole seismogram duration. Corresponding coda envelopes provide important information about the earth inhomogeneity, which can be stochastically modeled in terms of distribution of scatterers in a random medium. In suitable experimental conditions (i.e. high earth heterogeneity), either the two parameters describing heterogeneity (scattering coefficient), intrinsic energy dissipation (coefficient of intrinsic attenuation) or a combination of them (extinction length and seismic albedo) can be used to image Earth structures. Once a set of such parameter couples has been measured in a given area and for a number of sources and receivers, imaging their space distribution with standard methods is straightforward. However, as for finite-frequency and full-waveform tomography, the essential problem for a correct imaging is the determination of the weighting function describing the spatial sensitivity of observable data to scattering and absorption anomalies. Due to the nature of coda waves, the measured parameter couple can be seen as a weighted space average of the real parameters characterizing the rock volumes illuminated by the scattered waves. This paper uses the Monte Carlo numerical solution of the Energy Transport Equation to find approximate but realistic 2-D space-weighting functions for coda waves. Separate images for scattering and absorption based on these sensitivity functions are then compared with those obtained with commonly used sensitivity functions in an application to data from an active seismic experiment carried out at Deception Island (Antarctica). Results show that these novel functions are based on a reliable and physically grounded method to image magnitude and shape of scattering and absorption anomalies. Their

  17. Automated Multi-Contrast Brain Pathological Area Extraction from 2D MR Images

    Directory of Open Access Journals (Sweden)

    P. Dvořák

    2015-02-01

    Full Text Available The aim of this work is to propose the fully automated pathological area extraction from multi-parametric 2D MR images of brain. The proposed method is based on multi-resolution symmetry analysis and automatic thresholding. The proposed algorithm first detects the presence of pathology and then starts its extraction. T2 images are used for the presence detection and the multi-contrast MRI is used for the extraction, concretely T2 and FLAIR images. The extraction is based on thresholding, where Otsu's algorithm is used for the automatic determination of the threshold. Since the method is based on symmetry, it works for both axial and coronal planes. In both these planes of healthy brain, the approximate left-right symmetry exists and it is used as the prior knowledge for searching the approximate pathology location. It is assumed that this area is not located symmetrically in both hemispheres, which is met in most cases. The detection algorithm was tested on 203 T2-weighted images and reached the true positive rate of 87.52% and true negative rate of 93.14%. The extraction algorithm was tested on 357 axial and 443 coronal real images from publicly available BRATS databases containing 3D volumes brain tumor patients. The results were evaluated by Dice Coefficient (axial: 0.85 ± 0.11, coronal 0.82 ± 0.18 and by Accuracy (axial: 0.96 ± 0.05, coronal 0.94 ± 0.09.

  18. Model-based segmentation and quantification of subcellular structures in 2D and 3D fluorescent microscopy images

    Science.gov (United States)

    Wörz, Stefan; Heinzer, Stephan; Weiss, Matthias; Rohr, Karl

    2008-03-01

    We introduce a model-based approach for segmenting and quantifying GFP-tagged subcellular structures of the Golgi apparatus in 2D and 3D microscopy images. The approach is based on 2D and 3D intensity models, which are directly fitted to an image within 2D circular or 3D spherical regions-of-interest (ROIs). We also propose automatic approaches for the detection of candidates, for the initialization of the model parameters, and for adapting the size of the ROI used for model fitting. Based on the fitting results, we determine statistical information about the spatial distribution and the total amount of intensity (fluorescence) of the subcellular structures. We demonstrate the applicability of our new approach based on 2D and 3D microscopy images.

  19. Clinical evaluation of 2D versus 3D whole-body PET image quality using a dedicated BGO PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Visvikis, D. [CHU Morvan, U650 INSERM, Laboratoire de Traitement de l' Information Medicale (LaTIM), Brest (France); Griffiths, D. [Lister Healthcare, London PET Centre, London (United Kingdom); Costa, D.C. [Middlesex Hospital, Institute of Nuclear Medicine, Royal Free and University College Medical School, London (United Kingdom); HPP Medicina Molecular, SA Porto (Portugal); Bomanji, J.; Ell, P.J. [Middlesex Hospital, Institute of Nuclear Medicine, Royal Free and University College Medical School, London (United Kingdom)

    2005-09-01

    Three-dimensional positron emission tomography (3D PET) results in higher system sensitivity, with an associated increase in the detection of scatter and random coincidences. The objective of this work was to compare, from a clinical perspective, 3D and two-dimensional (2D) acquisitions in terms of whole-body (WB) PET image quality with a dedicated BGO PET system. 2D and 3D WB emission acquisitions were carried out in 70 patients. Variable acquisition parameters in terms of time of emission acquisition per axial field of view (aFOV) and slice overlap between sequential aFOVs were used during the 3D acquisitions. 3D and 2D images were reconstructed using FORE+WLS and OSEM respectively. Scatter correction was performed by convolution subtraction and a model-based scatter correction in 2D and 3D respectively. All WB images were attenuation corrected using segmented transmission scans. Images were blindly assessed by three observers for the presence of artefacts, confidence in lesion detection and overall image quality using a scoring system. Statistically significant differences between 2D and 3D image quality were only obtained for 3D emission acquisitions of 3 min. No statistically significant differences were observed for image artefacts or lesion detectability scores. Image quality correlated significantly with patient weight for both modes of operation. Finally, no differences were seen in image artefact scores for the different axial slice overlaps considered, suggesting the use of five slice overlaps in 3D WB acquisitions. 3D WB imaging using a dedicated BGO-based PET scanner offers similar image quality to that obtained in 2D considering similar overall times of acquisitions. (orig.)

  20. Assessment of prosthesis alignment after revision total knee arthroplasty using EOS 2D and 3D imaging: a reliability study.

    Directory of Open Access Journals (Sweden)

    Marrigje F Meijer

    Full Text Available INTRODUCTION: A new low-dose X-ray device, called EOS, has been introduced for determining lower-limb alignment in 2D and 3D. Reliability has not yet been assessed when using EOS on lower limbs containing a knee prosthesis. Therefore purpose of this study was to determine intraobserver and interobserver reliability of EOS 2D and 3D knee prosthesis alignment measurements after revision total knee arthroplasty (rTKA. METHODS: Forty anteroposterior and lateral images of 37 rTKA patients were included. Two observers independently performed measurements on these images twice. Varus/valgus angles were measured in 2D (VV2D and 3D (VV3D. Intraclass correlation coefficients and the Bland and Altman method were used to determine reliability. T-tests were used to test potential differences. RESULTS: Intraobserver and interobserver reliability were excellent for VV2D and VV3D. No significant difference or bias between the first and second measurements or the two observers was found. A significant mean and absolute difference of respectively 1.00° and 1.61° existed between 2D and 3D measurements. CONCLUSIONS: EOS provides reliable varus/valgus measurements in 2D and 3D for the alignment of the knee joint with a knee prosthesis. However, significant differences exist between varus/valgus measurements in 2D and 3D.

  1. Clinics in diagnostic imaging (175)

    Science.gov (United States)

    Krishnan, Vijay; Lim, Tze Chwan; Ho, Francis Cho Hao; Peh, Wilfred CG

    2017-01-01

    A 54-year-old man presented with change in behaviour, nocturnal enuresis, abnormal limb movement and headache of one week’s duration. The diagnosis of butterfly glioma (glioblastoma multiforme) was made based on imaging characteristics and was further confirmed by biopsy findings. As the corpus callosum is usually resistant to infiltration by tumours, a mass that involves and crosses the corpus callosum is suggestive of an aggressive neoplasm. Other neoplastic and non-neoplastic conditions that may involve the corpus callosum and mimic a butterfly glioma, as well as associated imaging features, are discussed. PMID:28361164

  2. 2D magnetotelluric inversion using reflection seismic images as constraints and application in the COSC project

    Science.gov (United States)

    Kalscheuer, Thomas; Yan, Ping; Hedin, Peter; Garcia Juanatey, Maria d. l. A.

    2017-04-01

    We introduce a new constrained 2D magnetotelluric (MT) inversion scheme, in which the local weights of the regularization operator with smoothness constraints are based directly on the envelope attribute of a reflection seismic image. The weights resemble those of a previously published seismic modification of the minimum gradient support method introducing a global stabilization parameter. We measure the directional gradients of the seismic envelope to modify the horizontal and vertical smoothness constraints separately. An appropriate choice of the new stabilization parameter is based on a simple trial-and-error procedure. Our proposed constrained inversion scheme was easily implemented in an existing Gauss-Newton inversion package. From a theoretical perspective, we compare our new constrained inversion to similar constrained inversion methods, which are based on image theory and seismic attributes. Successful application of the proposed inversion scheme to the MT field data of the Collisional Orogeny in the Scandinavian Caledonides (COSC) project using constraints from the envelope attribute of the COSC reflection seismic profile (CSP) helped to reduce the uncertainty of the interpretation of the main décollement. Thus, the new model gave support to the proposed location of a future borehole COSC-2 which is supposed to penetrate the main décollement and the underlying Precambrian basement.

  3. Clinics in diagnostic imaging (171)

    Science.gov (United States)

    Ooi, Su Kai Gideon; Tan, Tien Jin; Ngu, James Chi Yong

    2016-01-01

    A 46-year-old Chinese woman with a history of cholecystectomy and appendicectomy presented to the emergency department with symptoms of intestinal obstruction. Physical examination revealed central abdominal tenderness but no clinical features of peritonism. Plain radiography of the abdomen revealed a grossly distended large bowel loop with the long axis extending from the right lower abdomen toward the epigastrium, and an intraluminal air-fluid level. These findings were suspicious for an acute caecal volvulus, which was confirmed on subsequent contrast-enhanced computed tomography (CT) of the abdomen and pelvis. CT demonstrated an abnormal positional relationship between the superior mesenteric vein and artery, indicative of an underlying intestinal malrotation. This case highlights the utility of preoperative imaging in establishing the diagnosis of an uncommon cause of bowel obstruction. It also shows the importance of recognising the characteristic imaging features early, so as to ensure appropriate and expedient management, thus reducing patient morbidity arising from complications. PMID:27872936

  4. Diagnostic imaging of lipoma arborescens

    Energy Technology Data Exchange (ETDEWEB)

    Martin, S.; Hernandez, L.; Romero, J.; Lafuente, J.; Poza, A.I.; Ruiz, P. [Servicio de Radiodiagnostico, Hospital General Universitario Gregorio Maranon, c/Dr. Esquerdo, 46, E-28007 Madrid (Spain); Jimeno, M. [Servicio de Anatomia Patologica, Hospital General Universitario Gregorio Maranon, c/Dr. Esquerdo, 46, E-28007 Madrid (Spain)

    1998-06-01

    Objective. The imaging characteristics of lipoma arborescens using plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) are described. Design and patients. Five patients with a diagnosis of lipoma arborescens are presented. Three had monoarticular involvement of the knee joint. In the remaining two patients both knees and both hips, respectively, were affected. All patients were examined using plain radiographs and MRI. CT was employed in two cases. Results and conclusions. A conclusive diagnosis with exclusion of other synovial pathologies having similar clinical and radiological behaviour can be achieved on the basis of the MRI characteristics of lipoma arborescens. The aetiology of lipoma arborescens remains unknown, but its association with previous pathology of the affected joints in all our patients supports the theory of a non-neoplastic reactive process involving the synovial membrane. (orig.) With 5 figs., 18 refs.

  5. High Speed and Area Efficient 2D DWT Processor based Image Compression" Signal & Image Processing

    CERN Document Server

    Kaur, Sugreev

    2011-01-01

    This paper presents a high speed and area efficient DWT processor based design for Image Compression applications. In this proposed design, pipelined partially serial architecture has been used to enhance the speed along with optimal utilization and resources available on target FPGA. The proposed model has been designed and simulated using Simulink and System Generator blocks, synthesized with Xilinx Synthesis tool (XST) and implemented on Spartan 2 and 3 based XC2S100-5tq144 and XC3S500E-4fg320 target device. The results show that proposed design can operate at maximum frequency 231 MHz in case of Spartan 3 by consuming power of 117mW at 28 degree/c junction temperature. The result comparison has shown an improvement of 15% in speed.

  6. Analysis of 2-d ultrasound cardiac strain imaging using joint probability density functions.

    Science.gov (United States)

    Ma, Chi; Varghese, Tomy

    2014-06-01

    Ultrasound frame rates play a key role for accurate cardiac deformation tracking. Insufficient frame rates lead to an increase in signal de-correlation artifacts resulting in erroneous displacement and strain estimation. Joint probability density distributions generated from estimated axial strain and its associated signal-to-noise ratio provide a useful approach to assess the minimum frame rate requirements. Previous reports have demonstrated that bi-modal distributions in the joint probability density indicate inaccurate strain estimation over a cardiac cycle. In this study, we utilize similar analysis to evaluate a 2-D multi-level displacement tracking and strain estimation algorithm for cardiac strain imaging. The effect of different frame rates, final kernel dimensions and a comparison of radio frequency and envelope based processing are evaluated using echo signals derived from a 3-D finite element cardiac model and five healthy volunteers. Cardiac simulation model analysis demonstrates that the minimum frame rates required to obtain accurate joint probability distributions for the signal-to-noise ratio and strain, for a final kernel dimension of 1 λ by 3 A-lines, was around 42 Hz for radio frequency signals. On the other hand, even a frame rate of 250 Hz with envelope signals did not replicate the ideal joint probability distribution. For the volunteer study, clinical data was acquired only at a 34 Hz frame rate, which appears to be sufficient for radio frequency analysis. We also show that an increase in the final kernel dimensions significantly affect the strain probability distribution and joint probability density function generated, with a smaller effect on the variation in the accumulated mean strain estimated over a cardiac cycle. Our results demonstrate that radio frequency frame rates currently achievable on clinical cardiac ultrasound systems are sufficient for accurate analysis of the strain probability distribution, when a multi-level 2-D

  7. 2D-3D Medical Image Registration Based on GPU%基于GPU的2D-3D医学图像配准

    Institute of Scientific and Technical Information of China (English)

    党建武; 杭利华; 王阳萍; 杜晓刚

    2013-01-01

    In 2D-3D medical image registration, the DRR generation and the computation of the similarity measure between the DRR and the x-ray image are the most important and time-consuming registration procedures. Because of the problem of large amount of calculation in registration procedure, this paper combined the pattern intensity with gradient to simplify the calculation, and used GPU multithreading parallel computing to generate the DRR and comput the similarity on the GPU, introduced the gradient descent and multi-resolution strategies in the registration optimization procedure to complete the registration process. Compared with other similarity measures and registration on the CPU, this registration method ensures the registration precision and improves the registration speed.%在2D-3D医学图像配准中,数字影像重建(DRR)的生成与相似性测度是最重要同时也是最耗时的两个配准步骤.针对配准过程中计算量大、耗时长的问题,将模式强度与梯度相结合,简化模式强度相似性测度的计算量,同时利用图形处理器(GPU)的多线程并行计算在GPU上完成DRR生成与相似性测度,引入梯度下降与多分辨策略对配准过程进行优化,完成整个配准过程.通过与多种相似性测度方法以及基于CPU的配准的比较,表明该方法在很好地兼顾配准精确度的同时,配准速度得到了大大提高.

  8. A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging.

    Directory of Open Access Journals (Sweden)

    Elena Gallio

    Full Text Available Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies.

  9. A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging.

    Science.gov (United States)

    Gallio, Elena; Rampado, Osvaldo; Gianaria, Elena; Bianchi, Silvio Diego; Ropolo, Roberto

    2015-01-01

    Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems) were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies.

  10. FluoRender: An application of 2D image space methods for 3D and 4D confocal microscopy data visualization in neurobiology research

    KAUST Repository

    Wan, Yong

    2012-02-01

    2D image space methods are processing methods applied after the volumetric data are projected and rendered into the 2D image space, such as 2D filtering, tone mapping and compositing. In the application domain of volume visualization, most 2D image space methods can be carried out more efficiently than their 3D counterparts. Most importantly, 2D image space methods can be used to enhance volume visualization quality when applied together with volume rendering methods. In this paper, we present and discuss the applications of a series of 2D image space methods as enhancements to confocal microscopy visualizations, including 2D tone mapping, 2D compositing, and 2D color mapping. These methods are easily integrated with our existing confocal visualization tool, FluoRender, and the outcome is a full-featured visualization system that meets neurobiologists\\' demands for qualitative analysis of confocal microscopy data. © 2012 IEEE.

  11. Dynamic tracking of a deformable tissue based on 3D-2D MR-US image registration

    Science.gov (United States)

    Marami, Bahram; Sirouspour, Shahin; Fenster, Aaron; Capson, David W.

    2014-03-01

    Real-time registration of pre-operative magnetic resonance (MR) or computed tomography (CT) images with intra-operative Ultrasound (US) images can be a valuable tool in image-guided therapies and interventions. This paper presents an automatic method for dynamically tracking the deformation of a soft tissue based on registering pre-operative three-dimensional (3D) MR images to intra-operative two-dimensional (2D) US images. The registration algorithm is based on concepts in state estimation where a dynamic finite element (FE)- based linear elastic deformation model correlates the imaging data in the spatial and temporal domains. A Kalman-like filtering process estimates the unknown deformation states of the soft tissue using the deformation model and a measure of error between the predicted and the observed intra-operative imaging data. The error is computed based on an intensity-based distance metric, namely, modality independent neighborhood descriptor (MIND), and no segmentation or feature extraction from images is required. The performance of the proposed method is evaluated by dynamically deforming 3D pre-operative MR images of a breast phantom tissue based on real-time 2D images obtained from an US probe. Experimental results on different registration scenarios showed that deformation tracking converges in a few iterations. The average target registration error on the plane of 2D US images for manually selected fiducial points was between 0.3 and 1.5 mm depending on the size of deformation.

  12. Self-calibration of cone-beam CT geometry using 3D-2D image registration

    Science.gov (United States)

    Ouadah, S.; Stayman, J. W.; Gang, G. J.; Ehtiati, T.; Siewerdsen, J. H.

    2016-04-01

    Robotic C-arms are capable of complex orbits that can increase field of view, reduce artifacts, improve image quality, and/or reduce dose; however, it can be challenging to obtain accurate, reproducible geometric calibration required for image reconstruction for such complex orbits. This work presents a method for geometric calibration for an arbitrary source-detector orbit by registering 2D projection data to a previously acquired 3D image. It also yields a method by which calibration of simple circular orbits can be improved. The registration uses a normalized gradient information similarity metric and the covariance matrix adaptation-evolution strategy optimizer for robustness against local minima and changes in image content. The resulting transformation provides a ‘self-calibration’ of system geometry. The algorithm was tested in phantom studies using both a cone-beam CT (CBCT) test-bench and a robotic C-arm (Artis Zeego, Siemens Healthcare) for circular and non-circular orbits. Self-calibration performance was evaluated in terms of the full-width at half-maximum (FWHM) of the point spread function in CBCT reconstructions, the reprojection error (RPE) of steel ball bearings placed on each phantom, and the overall quality and presence of artifacts in CBCT images. In all cases, self-calibration improved the FWHM—e.g. on the CBCT bench, FWHM  =  0.86 mm for conventional calibration compared to 0.65 mm for self-calibration (p  <  0.001). Similar improvements were measured in RPE—e.g. on the robotic C-arm, RPE  =  0.73 mm for conventional calibration compared to 0.55 mm for self-calibration (p  <  0.001). Visible improvement was evident in CBCT reconstructions using self-calibration, particularly about high-contrast, high-frequency objects (e.g. temporal bone air cells and a surgical needle). The results indicate that self-calibration can improve even upon systems with presumably accurate geometric calibration and is

  13. Self-calibration of cone-beam CT geometry using 3D–2D image registration

    Science.gov (United States)

    Ouadah, S; Stayman, J W; Gang, G J; Ehtiati, T; Siewerdsen, J H

    2016-01-01

    Robotic C-arms are capable of complex orbits that can increase field of view, reduce artifacts, improve image quality, and/or reduce dose; however, it can be challenging to obtain accurate, reproducible geometric calibration required for image reconstruction for such complex orbits. This work presents a method for geometric calibration for an arbitrary source-detector orbit by registering 2D projection data to a previously acquired 3D image. It also yields a method by which calibration of simple circular orbits can be improved. The registration uses a normalized gradient information similarity metric and the covariance matrix adaptation-evolution strategy optimizer for robustness against local minima and changes in image content. The resulting transformation provides a ‘self-calibration’ of system geometry. The algorithm was tested in phantom studies using both a cone-beam CT (CBCT) test-bench and a robotic C-arm (Artis Zeego, Siemens Healthcare) for circular and non-circular orbits. Self-calibration performance was evaluated in terms of the full-width at half-maximum (FWHM) of the point spread function in CBCT reconstructions, the reprojection error (RPE) of steel ball bearings placed on each phantom, and the overall quality and presence of artifacts in CBCT images. In all cases, self-calibration improved the FWHM—e.g. on the CBCT bench, FWHM = 0.86 mm for conventional calibration compared to 0.65 mm for self-calibration (p < 0.001). Similar improvements were measured in RPE—e.g. on the robotic C-arm, RPE = 0.73 mm for conventional calibration compared to 0.55 mm for self-calibration (p < 0.001). Visible improvement was evident in CBCT reconstructions using self-calibration, particularly about high-contrast, high-frequency objects (e.g. temporal bone air cells and a surgical needle). The results indicate that self-calibration can improve even upon systems with presumably accurate geometric calibration and is applicable to situations where conventional

  14. Imaging diagnostics in ovarian cancer

    DEFF Research Database (Denmark)

    Fog, Sigrid Marie Kasper Kasper; Dueholm, Margit; Marinovskij, Edvard;

    2017-01-01

    OBJECTIVE: To analyze the ability of magnetic resonance imaging (MRI) and systematic evaluation at surgery to predict optimal cytoreduction in primary advanced ovarian cancer and to develop a preoperative scoring system for cancer staging. STUDY DESIGN: Preoperative MRI and standard laparotomy were...... performed in 99 women with either ovarian or primary peritoneal cancer. Using univariate and multivariate logistic regression analysis of a systematic description of the tumor in nine abdominal compartments obtained by MRI and during surgery plus clinical parameters, a scoring system was designed....... MRI is able to assess ovarian cancer with peritoneal carcinomatosis with satisfactory concordance with laparotomic findings. This scoring system could be useful as a clinical guideline and should be evaluated and developed further in larger studies....

  15. Marketing considerations for diagnostic imaging centers.

    Science.gov (United States)

    McCue, P

    1987-10-01

    Diagnostic imaging centers seek every possible advantage to maintain a successful practice in the face of competition from hospitals and other freestanding operators. Several radiologists and business managers involved in existing or planned centers discuss their marketing strategies, modality choices, organizational structure, and other issues pertinent to the start-up and operation of a viable free-standing operation.

  16. Determining ice water content from 2D crystal images in convective cloud systems

    Science.gov (United States)

    Leroy, Delphine; Coutris, Pierre; Fontaine, Emmanuel; Schwarzenboeck, Alfons; Strapp, J. Walter

    2016-04-01

    Cloud microphysical in-situ instrumentation measures bulk parameters like total water content (TWC) and/or derives particle size distributions (PSD) (utilizing optical spectrometers and optical array probes (OAP)). The goal of this work is to introduce a comprehensive methodology to compute TWC from OAP measurements, based on the dataset collected during recent HAIC (High Altitude Ice Crystals)/HIWC (High Ice Water Content) field campaigns. Indeed, the HAIC/HIWC field campaigns in Darwin (2014) and Cayenne (2015) provide a unique opportunity to explore the complex relationship between cloud particle mass and size in ice crystal environments. Numerous mesoscale convective systems (MCSs) were sampled with the French Falcon 20 research aircraft at different temperature levels from -10°C up to 50°C. The aircraft instrumentation included an IKP-2 (isokinetic probe) to get reliable measurements of TWC and the optical array probes 2D-S and PIP recording images over the entire ice crystal size range. Based on the known principle relating crystal mass and size with a power law (m=α•Dβ), Fontaine et al. (2014) performed extended 3D crystal simulations and thereby demonstrated that it is possible to estimate the value of the exponent β from OAP data, by analyzing the surface-size relationship for the 2D images as a function of time. Leroy et al. (2015) proposed an extended version of this method that produces estimates of β from the analysis of both the surface-size and perimeter-size relationships. Knowing the value of β, α then is deduced from the simultaneous IKP-2 TWC measurements for the entire HAIC/HIWC dataset. The statistical analysis of α and β values for the HAIC/HIWC dataset firstly shows that α is closely linked to β and that this link changes with temperature. From these trends, a generalized parameterization for α is proposed. Finally, the comparison with the initial IKP-2 measurements demonstrates that the method is able to predict TWC values

  17. Trilogy possible meteorite impact crater at Bukit Bunuh, Malaysia using 2-D electrical resistivity imaging

    Science.gov (United States)

    Jinmin, M.; Rosli, S.; Nordiana, M. M.; Mokhtar, S.

    2017-07-01

    Bukit Bunuh situated in Lenggong (Perak) is one of Malaysia's most important areas for archeology that revealed many traces of Malaysia's prehistory. Geophysical method especially 2-D electrical resistivity imaging method is non-destructive which is applied in geo-subsurface study for meteorite impact. The study consists of two stages which are regional and detail study with a total of fourteen survey lines. The survey lines were conducted using Pole-dipole array with 5 m minimum electrode spacing. The results of each stage are correlated and combined to produce detail subsurface resistivity distribution of the study area. It shows that the area consists of two main layers which are overburden and granitic bedrock. The first layer is overburden mix with boulders with resistivity value of 10-800 Ωm while the second layer is granitic bedrock with resistivity value of >1500 Ωm. This study also shows few spotted possibility of uplift (rebound) due to the high impact which suspected from meteorite. A lot of fracture were found within the survey area which could be one of the effect of meteorite impact. The result suggest that Bukit Bunuh is under layer by a complex crater with diameter of crater rim is approximately 5-6 km.

  18. A radiographic imaging system based upon a 2-D silicon microstrip sensor

    CERN Document Server

    Papanestis, A; Corrin, E; Raymond, M; Hall, G; Triantis, F A; Manthos, N; Evagelou, I; Van den Stelt, P; Tarrant, T; Speller, R D; Royle, G F

    2000-01-01

    A high resolution, direct-digital detector system based upon a 2-D silicon microstrip sensor has been designed, built and is undergoing evaluation for applications in dentistry and mammography. The sensor parameters and image requirements were selected using Monte Carlo simulations. Sensors selected for evaluation have a strip pitch of 50mum on the p-side and 80mum on the n-side. Front-end electronics and data acquisition are based on the APV6 chip and were adapted from systems used at CERN for high-energy physics experiments. The APV6 chip is not self-triggering so data acquisition is done at a fixed trigger rate. This paper describes the mammographic evaluation of the double sided microstrip sensor. Raw data correction procedures were implemented to remove the effects of dead strips and non-uniform response. Standard test objects (TORMAX) were used to determine limiting spatial resolution and detectability. MTFs were determined using the edge response. The results indicate that the spatial resolution of the...

  19. Depth map resolution enhancement for 2D/3D imaging system via compressive sensing

    Science.gov (United States)

    Han, Juanjuan; Loffeld, Otmar; Hartmann, Klaus

    2011-08-01

    This paper introduces a novel approach for post-processing of depth map which enhances the depth map resolution in order to achieve visually pleasing 3D models from a new monocular 2D/3D imaging system consists of a Photonic mixer device (PMD) range camera and a standard color camera. The proposed method adopts the revolutionary inversion theory framework called Compressive Sensing (CS). The depth map of low resolution is considered as the result of applying blurring and down-sampling techniques to that of high-resolution. Based on the underlying assumption that the high-resolution depth map is compressible in frequency domain and recent theoretical work on CS, the high-resolution version can be estimated and furthermore reconstructed via solving non-linear optimization problem. And therefore the improved depth map reconstruction provides a useful help to build an improved 3D model of a scene. The experimental results on the real data are presented. In the meanwhile the proposed scheme opens new possibilities to apply CS to a multitude of potential applications on various multimodal data analysis and processing.

  20. Large resistive 2D Micromegas with genetic multiplexing and some imaging applications

    Science.gov (United States)

    Bouteille, S.; Attié, D.; Baron, P.; Calvet, D.; Magnier, P.; Mandjavidze, I.; Procureur, S.; Riallot, M.

    2016-10-01

    The performance of the first large resistive Micromegas detectors with 2D readout and genetic multiplexing is presented. These detectors have a 50 × 50cm2 active area and are equipped with 1024 strips both in X- and Y-directions. The same genetic multiplexing pattern is applied on both coordinates, resulting in the compression of signals on 2 × 61 readout channels. Four such detectors have been built at CERN, and extensively tested with cosmics. The resistive strip film allows for very high gain operation, compensating for the charge spread on the 2 dimensions as well as the S / N loss due to the huge, 1 nF input capacitance. This film also creates a significantly different signal shape in the X- and Y-coordinates due to the charge evacuation along the resistive strips. All in all a detection efficiency above 95% is achieved with a 1 cm drift gap. Though not yet optimal, the measured 300 μm spatial resolution allows for very precise imaging in the field of muon tomography, and some applications of these detectors are presented.

  1. Stochastic rank correlation: a robust merit function for 2D/3D registration of image data obtained at different energies.

    Science.gov (United States)

    Birkfellner, Wolfgang; Stock, Markus; Figl, Michael; Gendrin, Christelle; Hummel, Johann; Dong, Shuo; Kettenbach, Joachim; Georg, Dietmar; Bergmann, Helmar

    2009-08-01

    In this article, the authors evaluate a merit function for 2D/3D registration called stochastic rank correlation (SRC). SRC is characterized by the fact that differences in image intensity do not influence the registration result; it therefore combines the numerical advantages of cross correlation (CC)-type merit functions with the flexibility of mutual-information-type merit functions. The basic idea is that registration is achieved on a random subset of the image, which allows for an efficient computation of Spearman's rank correlation coefficient. This measure is, by nature, invariant to monotonic intensity transforms in the images under comparison, which renders it an ideal solution for intramodal images acquired at different energy levels as encountered in intrafractional kV imaging in image-guided radiotherapy. Initial evaluation was undertaken using a 2D/3D registration reference image dataset of a cadaver spine. Even with no radiometric calibration, SRC shows a significant improvement in robustness and stability compared to CC. Pattern intensity, another merit function that was evaluated for comparison, gave rather poor results due to its limited convergence range. The time required for SRC with 5% image content compares well to the other merit functions; increasing the image content does not significantly influence the algorithm accuracy. The authors conclude that SRC is a promising measure for 2D/3D registration in IGRT and image-guided therapy in general.

  2. Wound Measurement Techniques: Comparing the Use of Ruler Method, 2D Imaging and 3D Scanner.

    Science.gov (United States)

    Shah, Aj; Wollak, C; Shah, J B

    2013-12-01

    The statistics on the growing number of non-healing wounds is alarming. In the United States, chronic wounds affect 6.5 million patients. An estimated US $25 billion is spent annually on treatment of chronic wounds and the burden is rapidly growing due to increasing health care costs, an aging population and a sharp rise in the incidence of diabetes and obesity worldwide.(1) Accurate wound measurement techniques will help health care personnel to monitor the wounds which will indirectly help improving care.(7,9) The clinical practice of measuring wounds has not improved even today.(2,3) A common method like the ruler method to measure wounds has poor interrater and intrarater reliability.(2,3) Measuring the greatest length by the greatest width perpendicular to the greatest length, the perpendicular method, is more valid and reliable than other ruler based methods.(2) Another common method like acetate tracing is more accurate than the ruler method but still has its disadvantages. These common measurement techniques are time consuming with variable inaccuracies. In this study, volumetric measurements taken with a non-contact 3-D scanner are benchmarked against the common ruler method, acetate grid tracing, and 2-D image planimetry volumetric measurement technique. A liquid volumetric fill method is used as the control volume. Results support the hypothesis that the 3-D scanner consistently shows accurate volumetric measurements in comparison to standard volumetric measurements obtained by the waterfill technique (average difference of 11%). The 3-D scanner measurement technique was found more reliable and valid compared to other three techniques, the ruler method (average difference of 75%), acetate grid tracing (average difference of 41%), and 2D planimetric measurements (average difference of 52%). Acetate tracing showed more accurate measurements compared to the ruler method (average difference of 41% (acetate tracing) compared to 75% (ruler method)). Improving

  3. Multifractal and Singularity Maps of soil surface moisture distribution derived from 2D image analysis.

    Science.gov (United States)

    Cumbrera, Ramiro; Millán, Humberto; Martín-Sotoca, Juan Jose; Pérez Soto, Luis; Sanchez, Maria Elena; Tarquis, Ana Maria

    2016-04-01

    methods for mapping geochemical anomalies caused by buried sources and for predicting undiscovered mineral deposits in covered areas. Journal of Geochemical Exploration, 122, 55-70. Cumbrera, R., Ana M. Tarquis, Gabriel Gascó, Humberto Millán (2012) Fractal scaling of apparent soil moisture estimated from vertical planes of Vertisol pit images. Journal of Hydrology (452-453), 205-212. Martin Sotoca; J.J. Antonio Saa-Requejo, Juan Grau and Ana M. Tarquis (2016). Segmentation of singularity maps in the context of soil porosity. Geophysical Research Abstracts, 18, EGU2016-11402. Millán, H., Cumbrera, R. and Ana M. Tarquis (2016) Multifractal and Levy-stable statistics of soil surface moisture distribution derived from 2D image analysis. Applied Mathematical Modelling, 40(3), 2384-2395.

  4. Circumferential 2D-strain imaging for the prediction of long term response to cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2008-06-01

    Full Text Available Abstract Background Cardiac Resynchronization Therapy (CRT leads to hemodynamic and clinical improvement in heart failure patients. The established methods to evaluate myocardial asynchrony analyze longitudinal and radial myocardial function. This study evaluates the new method of circumferential 2D-strain imaging in the prediction of the long-term response to CRT. Methods and results 38 heart failure patients (NYHA II-III, QRS > 120 ms, LVEF Conclusion There is a significant decrease in the circumferential 2D-strain derived delays after CRT, indicating that resynchronization induces improvement in all three dimensions of myocardial contraction. However, the resulting predictive values of 2D strain delays are not superior to longitudinal and radial 2D-strain or TDI delays.

  5. Application of conformal map theory for design of 2-D ultrasonic array structure for NDT imaging application: a feasibility study.

    Science.gov (United States)

    Ramadas, Sivaram N; Jackson, Joseph C; Dziewierz, Jerzy; O'Leary, Richard; Gachagan, Anthony

    2014-03-01

    Two-dimensional ultrasonic phased arrays are becoming increasingly popular in nondestructive evaluation (NDE). Sparse array element configurations are required to fully exploit the potential benefits of 2-D phased arrays. This paper applies the conformal mapping technique as a means of designing sparse 2-D array layouts for NDE applications. Modeling using both Huygens' field prediction theory and 2-D fast Fourier transformation is employed to study the resulting new structure. A conformal power map was used that, for fixed beam width, was shown in simulations to have a greater contrast than rectangular or random arrays. A prototype aperiodic 2-D array configuration for direct contact operation in steel, with operational frequency ~3 MHz, was designed using the array design principle described in this paper. Experimental results demonstrate a working sparse-array transducer capable of performing volumetric imaging.

  6. Comparison of 3D cube FLAIR with 2D FLAIR for multiple sclerosis imaging at 3 tesla

    Energy Technology Data Exchange (ETDEWEB)

    Patzig, M.; Brueckmann, H.; Fesl, G. [Muenchen Univ. (Germany). Dept. of Neuroradiology; Burke, M. [GE Healthcare, Solingen (Germany)

    2014-05-15

    Purpose: Three-dimensional (3 D) MRI sequences allow improved spatial resolution with good signal and contrast properties as well as multiplanar reconstruction. We sought to compare Cube, a 3 D FLAIR sequence, to a standard 2 D FLAIR sequence in multiple sclerosis (MS) imaging. Materials and Methods: Examinations were performed in the clinical routine on a 3.0 Tesla scanner. 12 patients with definite MS were included. Lesions with MS-typical properties on the images of Cube FLAIR and 2 D FLAIR sequences were counted and allocated to different brain regions. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated. Results: With 384 the overall number of lesions found with Cube FLAIR was significantly higher than with 2 D FLAIR (N = 221). The difference was mostly accounted for by supratentorial lesions (N = 372 vs. N = 216) while the infratentorial lesion counts were low in both sequences. SNRs and CNRs were significantly higher in CUBE FLAIR with the exception of the CNR of lesion to gray matter, which was not significantly different. Conclusion: Cube FLAIR showed a higher sensitivity for MS lesions compared to a 2 D FLAIR sequence. 3 D FLAIR might replace 2 D FLAIR sequences in MS imaging in the future. (orig.)

  7. Register cardiac fiber orientations from 3D DTI volume to 2D ultrasound image of rat hearts

    Science.gov (United States)

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-03-01

    Two-dimensional (2D) ultrasound or echocardiography is one of the most widely used examinations for the diagnosis of cardiac diseases. However, it only supplies the geometric and structural information of the myocardium. In order to supply more detailed microstructure information of the myocardium, this paper proposes a registration method to map cardiac fiber orientations from three-dimensional (3D) magnetic resonance diffusion tensor imaging (MR-DTI) volume to the 2D ultrasound image. It utilizes a 2D/3D intensity based registration procedure including rigid, log-demons, and affine transformations to search the best similar slice from the template volume. After registration, the cardiac fiber orientations are mapped to the 2D ultrasound image via fiber relocations and reorientations. This method was validated by six images of rat hearts ex vivo. The evaluation results indicated that the final Dice similarity coefficient (DSC) achieved more than 90% after geometric registrations; and the inclination angle errors (IAE) between the mapped fiber orientations and the gold standards were less than 15 degree. This method may provide a practical tool for cardiologists to examine cardiac fiber orientations on ultrasound images and have the potential to supply additional information for diagnosis of cardiac diseases.

  8. Automatic 2D segmentation of airways in thorax computed tomography images; Segmentacao automatica 2D de vias aereas em imagens de tomografia computadorizada do torax

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcante, Tarique da Silveira; Cortez, Paulo Cesar; Almeida, Thomaz Maia de, E-mail: tarique@lesc.ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia de Teleinformatica; Felix, John Hebert da Silva [Universidade da Integracao Internacional da Lusofonia Afro-Brasileira (UNILAB), Redencao, CE (Brazil). Departamento de Energias; Holanda, Marcelo Alcantara [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Fac. de Medicina

    2013-07-01

    Introduction: much of the world population is affected by pulmonary diseases, such as the bronchial asthma, bronchitis and bronchiectasis. The bronchial diagnosis is based on the airways state. In this sense, the automatic segmentation of the airways in Computed Tomography (CT) scans is a critical step in the aid to diagnosis of these diseases. Methods: this paper evaluates algorithms for airway automatic segmentation, using Neural Network Multilayer Perceptron (MLP) and Lung Densities Analysis (LDA) for detecting airways, along with Region Growing (RG), Active Contour Method (ACM) Balloon and Topology Adaptive to segment them. Results: we obtained results in three stages: comparative analysis of the detection algorithms MLP and LDA, with a gold standard acquired by three physicians with expertise in CT imaging of the chest; comparative analysis of segmentation algorithms ACM Balloon, ACM Topology Adaptive, MLP and RG; and evaluation of possible combinations between segmentation and detection algorithms, resulting in the complete method for automatic segmentation of the airways in 2D. Conclusion: the low incidence of false negative and the significant reduction of false positive, results in similarity coefficient and sensitivity exceeding 91% and 87% respectively, for a combination of algorithms with satisfactory segmentation quality. (author)

  9. Refraction-based 2D, 2.5D and 3D medical imaging: Stepping forward to a clinical trial

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Masami [Tokyo University of Science, Research Institute for Science and Technology, Noda, Chiba 278-8510 (Japan)], E-mail: msm-ando@rs.noda.tus.ac.jp; Bando, Hiroko [Tsukuba University (Japan); Tokiko, Endo; Ichihara, Shu [Nagoya Medical Center (Japan); Hashimoto, Eiko [GUAS (Japan); Hyodo, Kazuyuki [KEK (Japan); Kunisada, Toshiyuki [Okayama University (Japan); Li Gang [BSRF (China); Maksimenko, Anton [Tokyo University of Science, Research Institute for Science and Technology, Noda, Chiba 278-8510 (Japan); KEK (Japan); Mori, Kensaku [Nagoya University (Japan); Shimao, Daisuke [IPU (Japan); Sugiyama, Hiroshi [KEK (Japan); Yuasa, Tetsuya [Yamagata University (Japan); Ueno, Ei [Tsukuba University (Japan)

    2008-12-15

    An attempt at refraction-based 2D, 2.5D and 3D X-ray imaging of articular cartilage and breast carcinoma is reported. We are developing very high contrast X-ray 2D imaging with XDFI (X-ray dark-field imaging), X-ray CT whose data are acquired by DEI (diffraction-enhanced imaging) and tomosynthesis due to refraction contrast. 2D and 2.5D images were taken with nuclear plates or with X-ray films. Microcalcification of breast cancer and articular cartilage are clearly visible. 3D data were taken with an X-ray sensitive CCD camera. The 3D image was successfully reconstructed by the use of an algorithm newly made by our group. This shows a distinctive internal structure of a ductus lactiferi (milk duct) that contains inner wall, intraductal carcinoma and multifocal calcification in the necrotic core of the continuous DCIS (ductal carcinoma in situ). Furthermore consideration of clinical applications of these contrasts made us to try tomosynthesis. This attempt was satisfactory from the view point of articular cartilage image quality and the skin radiation dose.

  10. A novel technique for single-shot energy-resolved 2D X-ray imaging of plasmas relevant for the Inertial Confinement Fusion

    CERN Document Server

    Labate, L; Levato, T; Gizzi, L A

    2012-01-01

    A novel X-ray diagnostic of laser-fusion plasmas is described, allowing 2D monochromatic images of hot, dense plasmas to be obtained in any X-ray photon energy range, over a large domain, on a single-shot basis. The device (named Energy-encoded Pinhole Camera - EPiC) is based upon the use of an array of many pinholes coupled to a large area CCD camera operating in the single-photon mode. The available X-ray spectral domain is only limited by the Quantum Efficiency of scientific-grade X-ray CCD cameras, thus extending from a few keV up to a few tens of keV. Spectral 2D images of the emitting plasma can be obtained at any X-ray photon energy provided that a sufficient number of photons had been collected at the desired energy. Results from recent ICF related experiments will be reported in order to detail the new diagnostic.

  11. Diagnostic imaging of craniopharyngioma; Diagnostyka obrazowa czaszkogardlakow

    Energy Technology Data Exchange (ETDEWEB)

    Gradzki, J.; Nowak, S.; Paprzycki, W. [Akademia Medyczna, Poznan (Poland)

    1993-12-31

    40 patients have been examined with operational and histological confirmation of craniopharyngioma. CT image and X-ray plane of skull were performed in case all of these patients. TMR was conformed to examine 4 patients. X-ray planes was compared to CT. CT permits tumor cyst detection. The efficacy of mentioned above diagnostic techniques was compared with surgical findings. (author). 7 refs, 5 figs, 2 tabs.

  12. Advanced 3-D Ultrasound Imaging: 3-D Synthetic Aperture Imaging using Fully Addressed and Row-Column Addressed 2-D Transducer Arrays

    DEFF Research Database (Denmark)

    Bouzari, Hamed

    with transducer arrays using this addressing scheme, when integrated into probe handles. For that reason, two in-house prototyped 62+62 row-column addressed 2-D array transducer probes were manufactured using capacitive micromachined ultrasonic transducer (CMUT) and piezoelectric transducer (PZT) technology...... in many clinical applications. Real-time 3-D ultrasound imaging is still not as widespread in use in the clinics as 2-D ultrasound imaging. Two limiting factors have traditionally been the low image quality as well as low volume rate achievable with a 2-D transducer array using the conventional 3-D...... and measurements with the ultrasound research scanner SARUS and a 3.8 MHz 1024 element 2-D transducer array. In all investigations, 3-D synthetic aperture imaging achieved a better resolution, lower side-lobes, higher contrast, and better signal to noise ratio than parallel beamforming. This is achieved partly...

  13. Feasibility and limitations of an automated 2D-3D rigid image registration system for complex endovascular aortic procedures.

    Science.gov (United States)

    Carrell, Tom W G; Modarai, Bijan; Brown, James R I; Penney, Graeme P

    2010-08-01

    To examine the feasibility of an automated 2-dimensional (2D) to 3- dimensional (3D) image registration system to simplify the navigational challenges faced in complex endovascular aortic procedures. An automated 2D-3D image registration system was used to overlay pre-acquired 3D computed tomography images onto fluoroscopy images taken during endovascular aneurysm repair. Errors between the 3D overlay and digital subtraction angiograms were measured and correlated with aortic neck angulation. A mean discrepancy r = 0.75). Aortas with a maximum neck angulation 30 degrees had a mean error of 6.2+/-2.5 mm (p<0.0001). The major source of registration errors is aortic deformation caused by the presence of the introducer and endovascular graft. Further work is required if this technology is to be routinely applied to severely angulated aortic anatomy.

  14. Pose-aware C-arm for automatic re-initialization of interventional 2D/3D image registration.

    Science.gov (United States)

    Fotouhi, Javad; Fuerst, Bernhard; Johnson, Alex; Lee, Sing Chun; Taylor, Russell; Osgood, Greg; Navab, Nassir; Armand, Mehran

    2017-07-01

    In minimally invasive interventions assisted by C-arm imaging, there is a demand to fuse the intra-interventional 2D C-arm image with pre-interventional 3D patient data to enable surgical guidance. The commonly used intensity-based 2D/3D registration has a limited capture range and is sensitive to initialization. We propose to utilize an opto/X-ray C-arm system which allows to maintain the registration during intervention by automating the re-initialization for the 2D/3D image registration. Consequently, the surgical workflow is not disrupted and the interaction time for manual initialization is eliminated. We utilize two distinct vision-based tracking techniques to estimate the relative poses between different C-arm arrangements: (1) global tracking using fused depth information and (2) RGBD SLAM system for surgical scene tracking. A highly accurate multi-view calibration between RGBD and C-arm imaging devices is achieved using a custom-made multimodal calibration target. Several in vitro studies are conducted on pelvic-femur phantom that is encased in gelatin and covered with drapes to simulate a clinically realistic scenario. The mean target registration errors (mTRE) for re-initialization using depth-only and RGB [Formula: see text] depth are 13.23 mm and 11.81 mm, respectively. 2D/3D registration yielded 75% success rate using this automatic re-initialization, compared to a random initialization which yielded only 23% successful registration. The pose-aware C-arm contributes to the 2D/3D registration process by globally re-initializing the relationship of C-arm image and pre-interventional CT data. This system performs inside-out tracking, is self-contained, and does not require any external tracking devices.

  15. Real-time registration of 3D to 2D ultrasound images for image-guided prostate biopsy.

    Science.gov (United States)

    Gillies, Derek J; Gardi, Lori; De Silva, Tharindu; Zhao, Shuang-Ren; Fenster, Aaron

    2017-09-01

    During image-guided prostate biopsy, needles are targeted at tissues that are suspicious of cancer to obtain specimen for histological examination. Unfortunately, patient motion causes targeting errors when using an MR-transrectal ultrasound (TRUS) fusion approach to augment the conventional biopsy procedure. This study aims to develop an automatic motion correction algorithm approaching the frame rate of an ultrasound system to be used in fusion-based prostate biopsy systems. Two modes of operation have been investigated for the clinical implementation of the algorithm: motion compensation using a single user initiated correction performed prior to biopsy, and real-time continuous motion compensation performed automatically as a background process. Retrospective 2D and 3D TRUS patient images acquired prior to biopsy gun firing were registered using an intensity-based algorithm utilizing normalized cross-correlation and Powell's method for optimization. 2D and 3D images were downsampled and cropped to estimate the optimal amount of image information that would perform registrations quickly and accurately. The optimal search order during optimization was also analyzed to avoid local optima in the search space. Error in the algorithm was computed using target registration errors (TREs) from manually identified homologous fiducials in a clinical patient dataset. The algorithm was evaluated for real-time performance using the two different modes of clinical implementations by way of user initiated and continuous motion compensation methods on a tissue mimicking prostate phantom. After implementation in a TRUS-guided system with an image downsampling factor of 4, the proposed approach resulted in a mean ± std TRE and computation time of 1.6 ± 0.6 mm and 57 ± 20 ms respectively. The user initiated mode performed registrations with in-plane, out-of-plane, and roll motions computation times of 108 ± 38 ms, 60 ± 23 ms, and 89 ± 27 ms, respectively, and corresponding

  16. Comparison of Simultaneous and Sequential Two-View Registration for 3D/2D Registration of Vascular Images

    OpenAIRE

    Pathak, Chetna; Van Horn, Mark; Weeks, Susan; Bullitt, Elizabeth

    2005-01-01

    Accurate 3D/2D vessel registration is complicated by issues of image quality, occlusion, and other problems. This study performs a quantitative comparison of 3D/2D vessel registration in which vessels segmented from preoperative CT or MR are registered with biplane x-ray angiograms by either a) simultaneous two-view registration with advance calculation of the relative pose of the two views, or b) sequential registration with each view. We conclude on the basis of phantom studies that, even i...

  17. Active imaging for monitoring and technical diagnostics

    Directory of Open Access Journals (Sweden)

    Marek Piszczek

    2014-08-01

    Full Text Available The article presents the results of currently running work in the field of active imaging. The term active refers to both the image acquisition methods, so-called methods of the spatio-temporal framing and active visualization method applying augmented reality. Also results of application of the HMD and 6DoF modules as well as the experimental laser photography device are given. The device works by methods of spatio-temporal framing and it has been developed at the IOE WAT. In terms of image acquisition - active imaging involves the use of illumination of the observed scene. In the field of information visualization - active imaging directly concerns the issues of interaction human-machine environment. The results show the possibility of using the described techniques, among others, rescue (fire brigade, security of mass events (police or the protection of critical infrastructure as well as broadly understood diagnostic problems. Examples presented in the article show a wide range of possible uses of the methods both in observational techniques and measurement. They are relatively innovative solutions and require elaboration of series of hardware and algorithmic issues. However, already at this stage it is clear that active acquisition and visualization methods indicate a high potential for this type of information solutions.[b]Keywords[/b]: active imaging, augmented reality, digital image processing

  18. 2D Non-Separable Block-Lifting Structure and Its Application to M-Channel Perfect Reconstruction Filter Banks for Lossy-to-Lossless Image Coding.

    Science.gov (United States)

    Suzuki, Taizo; Kudo, Hiroyuki

    2015-12-01

    We propose a 2D non-separable block-lifting structure (2D-NSBL) that is easily formulated from the 1D separable block-lifting structure (1D-SBL) and 2D non-separable lifting structure (2D-NSL). The 2D-NSBL can be regarded as an extension of the 2D-NSL, because a two-channel 2D-NSBL is completely equivalent to a 2D-NSL. We apply the 2D-NSBL to M-channel ( M=2(n), n ∈ N) perfect reconstruction filter banks (PRFBs). The 2D-NSBL-based PRFBs outperform 1D-SBL-based PRFBs at lossy-to-lossless coding, whose image quality is scalable from lossless data to high compressed lossy data, because their rounding errors are reduced by merging many rounding operations.

  19. Image enhancement of digital periapical radiographs according to diagnostic tasks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-03-15

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  20. Infrared imaging diagnostics for INTF ion beam

    Science.gov (United States)

    Sudhir, D.; Bandyopadhyay, M.; Pandey, R.; Joshi, J.; Yadav, A.; Rotti, C.; Bhuyan, M.; Bansal, G.; Soni, J.; Tyagi, H.; Pandya, K.; Chakraborty, A.

    2015-04-01

    In India, testing facility named INTF [1] (Indian test facility) is being built in Institute for Plasma Research to characterize ITER-Diagnostic Neutral Beam (DNB). INTF is expected to deliver 60A negative hydrogen ion beam current of energy 100keV. The beam will be operated with 5Hz modulation having 3s ON/20s OFF duty cycle. To characterize the beam parameters several diagnostics are at different stages of design and development. One of them will be a beam dump, made of carbon fiber composite (CFC) plates placed perpendicular to the beam direction at a distance lm approximately. The beam dump needs to handle ˜ 6MW of beam power with peak power density ˜ 38.5MW/m2. The diagnostic is based on thermal (infra-red - IR) imaging of the footprint of the 1280 beamlets falling on the beam dump using four IR cameras from the rear side of the dump. The beam dump will be able to measure beam uniformity, beamlet divergence. It may give information on relative variation of negative ion stripping losses for different beam pulses. The design of this CFC based beam dump needs to address several physics and engineering issues, including some specific inputs from manufacturers. The manuscript will describe an overview of the diagnostic system and its design methodology highlighting those issues and the present status of its development.

  1. Estimation of 3-D pore network coordination number of rocks from watershed segmentation of a single 2-D image

    Science.gov (United States)

    Rabbani, Arash; Ayatollahi, Shahab; Kharrat, Riyaz; Dashti, Nader

    2016-08-01

    In this study, we have utilized 3-D micro-tomography images of real and synthetic rocks to introduce two mathematical correlations which estimate the distribution parameters of 3-D coordination number using a single 2-D cross-sectional image. By applying a watershed segmentation algorithm, it is found that the distribution of 3-D coordination number is acceptably predictable by statistical analysis of the network extracted from 2-D images. In this study, we have utilized 25 volumetric images of rocks in order to propose two mathematical formulas. These formulas aim to approximate the average and standard deviation of coordination number in 3-D pore networks. Then, the formulas are applied for five independent test samples to evaluate the reliability. Finally, pore network flow modeling is used to find the error of absolute permeability prediction using estimated and measured coordination numbers. Results show that the 2-D images are considerably informative about the 3-D network of the rocks and can be utilized to approximate the 3-D connectivity of the porous spaces with determination coefficient of about 0.85 that seems to be acceptable considering the variety of the studied samples.

  2. Accurate Angle Estimator for High-Frame-rate 2-D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando; Stuart, Matthias Bo; Lindskov Hansen, Kristoffer

    2016-01-01

    This paper presents a novel approach for estimating 2-D flow angles using a high-frame-rate ultrasound method. The angle estimator features high accuracy and low standard deviation (SD) over the full 360° range. The method is validated on Field II simulations and phantom measurements using the ex...

  3. Uncertainty in 2D hydrodynamic models from errors in roughness parameterization based on aerial images

    NARCIS (Netherlands)

    Straatsma, M.W.; Huthoff, F.

    2011-01-01

    In The Netherlands, 2D-hydrodynamic simulations are used to evaluate the effect of potential safety measures against river floods. In the investigated scenarios, the floodplains are completely inundated, thus requiring realistic representations of hydraulic roughness of floodplain vegetation. The cu

  4. Filters in 2D and 3D Cardiac SPECT Image Processing

    OpenAIRE

    Maria Lyra; Agapi Ploussi; Maritina Rouchota; Stella Synefia

    2014-01-01

    Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT) evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the de...

  5. Assessment of some problematic factors in facial image identification using a 2D/3D superimposition technique.

    Science.gov (United States)

    Atsuchi, Masaru; Tsuji, Akiko; Usumoto, Yosuke; Yoshino, Mineo; Ikeda, Noriaki

    2013-09-01

    The number of criminal cases requiring facial image identification of a suspect has been increasing because a surveillance camera is installed everywhere in the city and furthermore, the intercom with the recording function is installed in the home. In this study, we aimed to analyze the usefulness of a 2D/3D facial image superimposition system for image identification when facial aging, facial expression, and twins are under consideration. As a result, the mean values of the average distances calculated from the 16 anatomical landmarks between the 3D facial images of the 50s groups and the 2D facial images of the 20s, 30s, and 40s groups were 2.6, 2.3, and 2.2mm, respectively (facial aging). The mean values of the average distances calculated from 12 anatomical landmarks between the 3D normal facial images and four emotional expressions were 4.9 (laughter), 2.9 (anger), 2.9 (sadness), and 3.6mm (surprised), respectively (facial expressions). The average distance obtained from 11 anatomical landmarks between the same person in twins was 1.1mm, while the average distance between different person in twins was 2.0mm (twins). Facial image identification using the 2D/3D facial image superimposition system demonstrated adequate statistical power and identified an individual with high accuracy, suggesting its usefulness. However, computer technology concerning video image processing and superimpose progress, there is a need to keep familiar with the morphology and anatomy as its base.

  6. Numerical correction of anti-symmetric aberrations in single HRTEM images of weakly scattering 2D-objects

    Energy Technology Data Exchange (ETDEWEB)

    Lehtinen, Ossi, E-mail: ossi.lehtinen@gmail.com [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm (Germany); Geiger, Dorin; Lee, Zhongbo [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm (Germany); Whitwick, Michael Brian; Chen, Ming-Wei; Kis, Andras [Electrical Engineering Institute, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Kaiser, Ute [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm (Germany)

    2015-04-15

    Here, we present a numerical post-processing method for removing the effect of anti-symmetric residual aberrations in high-resolution transmission electron microscopy (HRTEM) images of weakly scattering 2D-objects. The method is based on applying the same aberrations with the opposite phase to the Fourier transform of the recorded image intensity and subsequently inverting the Fourier transform. We present the theoretical justification of the method, and its verification based on simulated images in the case of low-order anti-symmetric aberrations. Ultimately the method is applied to experimental hardware aberration-corrected HRTEM images of single-layer graphene and MoSe{sub 2} resulting in images with strongly reduced residual low-order aberrations, and consequently improved interpretability. Alternatively, this method can be used to estimate by trial and error the residual anti-symmetric aberrations in HRTEM images of weakly scattering objects.

  7. Integration of 3D and 2D imaging data for assured navigation in unknown environments: initial steps

    Science.gov (United States)

    Dill, Evan; Uijt de Haag, Maarten

    2009-05-01

    This paper discusses the initial steps of the development of a novel navigation method that integrates three-dimensional (3D) point cloud data, two-dimensional (2D) gray-level (intensity), and data from an Inertial Measurement Unit (IMU). A time-of-flight camera such as MESA's Swissranger will output both the 3D and 2D data. The target application is position and attitude determination of unmanned aerial vehicles (UAV) and autonomous ground vehicles (AGV) in urban or indoor environments. In urban and indoor environments a GPS position capability may not only be unavailable due to shadowing, significant signal attenuation or multipath, but also due to intentional denial or deception. The proposed algorithm extracts key features such as planar surfaces, lines and corner-points from both the 3D (point-cloud) and 2D (intensity) imagery. Consecutive observations of corresponding features in the 3D and 2D image frames are then used to compute estimates of position and orientation changes. Since the use of 3D image features for positioning suffers from limited feature observability resulting in deteriorated position accuracies, and the 2D imagery suffers from an unknown depth when estimating the pose from consecutive image frames, it is expected that the integration of both data sets will alleviate the problems with the individual methods resulting in an position and attitude determination method with a high level of assurance. An Inertial Measurement Unit (IMU) is used to set up the tracking gates necessary to perform data association of the features in consecutive frames. Finally, the position and orientation change estimates can be used to correct for the IMU drift errors.

  8. SU-E-T-431: Feasiblity of Using CT Scout Images for 2D LDR Brachytherpay Planning

    Energy Technology Data Exchange (ETDEWEB)

    Ha, J; Weaver, R [LAC+USC Medical Center, Los Angeles, CA, M. Mariscal (United States)

    2015-06-15

    Purpose: i) To show the feasibility of using CT scout images for 2D low-dose rate brachytherapy planning with BrachyVision (version 10.4); ii) to show their advantages and disadvantages over DRRs. Methods: A phantom was constructed to house a Fletcher-Suite applicator. The phantom is made of Styrofoam with metal BBs positioned at well-defined separations. These markers are used to assess the image distortion in the scout images. Unlike DRRs, scout images are distorted only in the direction normal to the couch direction; therefore, they needed to be scaled unidirectionally prior to importing into BrachyVision. In addition to confirming the scaling is performed correctly by measuring distances between well-positioned BB, we also compare a LDR plan using scout images to a 3D CT-based plan. Results: There is no distortion of the image along the couch direction due to the collimation of the CT scanner. The distortion in the transverse plane can be corrected by multiplying by the ratio of distances between source-to-isocenter and source-to-detector. The results show the distance separations between BBs as measured in scout images and by a caliber are within a few millimeters. Dosimetrically, the difference between the dose rates to points A and B based on scout images and on 3D CT are less than a few percents. The accuracy can be improved by correcting for the distortion on the transverse plane. Conclusion: It is possible to use CT scout images for 2D planning in BrachyVision. This is an advantage because scout images have no metal artifacts often present in CT images or DRRs. Another advantage is the lack of distortion in the couch direction. One major disadvantage is that the image distortion due to beam divergence can be large. This is due to the inherent short distance between source-to-isocenter and source-to-detector on a CT scanner.

  9. Tracking objects outside the line of sight using 2D intensity images

    Science.gov (United States)

    Klein, Jonathan; Peters, Christoph; Martín, Jaime; Laurenzis, Martin; Hullin, Matthias B.

    2016-08-01

    The observation of objects located in inaccessible regions is a recurring challenge in a wide variety of important applications. Recent work has shown that using rare and expensive optical setups, indirect diffuse light reflections can be used to reconstruct objects and two-dimensional (2D) patterns around a corner. Here we show that occluded objects can be tracked in real time using much simpler means, namely a standard 2D camera and a laser pointer. Our method fundamentally differs from previous solutions by approaching the problem in an analysis-by-synthesis sense. By repeatedly simulating light transport through the scene, we determine the set of object parameters that most closely fits the measured intensity distribution. We experimentally demonstrate that this approach is capable of following the translation of unknown objects, and translation and orientation of a known object, in real time.

  10. 2D MEMS electrostatic cantilever waveguide scanner for potential image display application

    Directory of Open Access Journals (Sweden)

    Gu Kebin

    2015-01-01

    Full Text Available This paper presents the current status of our micro-fabricated SU-8 2D electrostatic cantilever waveguide scanner. The current design utilizes a monolithically integrated electrostatic push-pull actuator. A 4.0 μm SU-8 rib waveguide design allows a relatively large core cross section (4μm in height and 20 μm in width to couple with existing optical fiber and a broad band single mode operation (λ= 0.7μm to 1.3μm with minimal transmission loss (85% to 87% output transmission efficiency with Gaussian beam profile input. A 2D scanning motion has been successfully demonstrated with two fundamental resonances found at 202 and 536 Hz in vertical and horizontal directions. A 130 μm and 19 μm, corresponding displacement and 0.062 and 0.009 rad field of view were observed at a +150V input. Beam divergence from the waveguide was corrected by a focusing GRIN lens and a 5μm beam diameter is observed at the focal plane. The transmission efficiency is low (~10% and cantilever is slightly under tensile residual stress due to inherent imperfection in the process and tooling in fabrication. However, 2D light scanning pattern was successfully demonstrated using 1-D push-pull actuation.

  11. Usefulness of diagnostic imaging in primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Sekiyama, Kazuya; Akakura, Koichiro; Mikami, Kazuo; Mizoguchi, Ken-ichi; Tobe, Toyofusa; Nakano, Koichi; Numata, Tsutomu; Konno, Akiyoshi; Ito, Haruo [Chiba Univ. (Japan). Graduate School of Medicine

    2003-01-01

    In patients with primary hyperparathyroidism, prevention of urinary stone recurrence can be achieved by surgical removal of the enlarged parathyroid gland. To ensure the efficacy of surgery for primary hyperparathyroidism, preoperative localization of the enlarged gland is important. In the present study, usefulness of diagnostic imaging for localization of the enlarged gland was investigated in primary hyperparathyroidism. We retrospectively examined the findings of imaging studies and clinical records in 79 patients (97 glands) who underwent surgical treatment for primary hyperparathyroidism at Chiba University Hospital between 1976 and 2000. The detection rates of accurate localization were investigated for imaging techniques, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI) thallium-201 and technetium-99m pertechnetate (Tl-Tc) subtraction scintigraphy and {sup 99m}Tc-methoxyisobutylisonitrile (MIBI) scintigraphy, and analysed in relation to the size and weight of the gland and pathological diagnosis. The detection rates by US, CT, MRI, Tl-Tc subtraction scintigraphy and MIBI scintigraphy were 70%, 67%, 73%, 38% and 78%, respectively. The overall detection rate changed from 50% to 88% before and after 1987. The detection rate of MIBI scintigraphy was superior to Tl-Tc subtraction scintigraphy. In primary hyperparathyroidism, improvement of accurate localization of an enlarged parathyroid gland was demonstrated along with recent advances in imaging techniques including MIBI scintigraphy. (author)

  12. Application of 2D/3D Image Registration in the Radiotherapy of Nasopharyngeal Carcinoma%2D/3D影像配准在鼻咽癌放疗中的应用

    Institute of Scientific and Technical Information of China (English)

    马广栋; 洪莉; 王亮和

    2013-01-01

    目的:研究2D/3D像配准方法对鼻咽癌放疗中计划靶区PTV外扩距离的影响。方法应用OBI (On Board Image,OBI)系统获取2D影像(kV图像和PV图像)和3D影像(CBCT图像),将获取的2D和3D影像分别经DRR配准系统和模拟定位CT进行图像配准,确定前后、头脚、左右3个方向上的摆位误差,再由2种PTV外扩公式计算3个方向上的PTV外扩距离。结果2D和3D影像配准的PTV外扩值有所不同。kV,PV,CBCT三者配准误差相互比较P>0.05,无统计学意义。结论kV图像和PV图像和CBCT图像都能很好地验证照射野位置。CBCT图像可以分析三维方向的影像误差,降低了2D图像影像重叠产生的摆位误差的影响。%Objective To study the effect of 2D/3D image registration on the extended distance of planning target volume (PTV) in the radiotherapy of nasopharyngeal carcinoma (NPC). Methods Using OBI system to obtain two-dimensional images (kV images and PV images) and three-dimensional images (CBCT images). Then registering 2D and 3D images by using DRR registration system and simulation positioning CT respectively to get the set-up errors of VRT, LNG, LAT. Then calculating the values of PTV extended distance of VRT, LNG, LAT with two kinds of PTV expansion formulas. Results The values of PTV extended distance between 2D and 3D images are different while there is no signiifcance in registration errors among kV, PV, CBCT images (P>0.05). Conclusion Both of 2D images (kV images and PV images) and 3D images (CBCT images) can verify the radiation field well. 3D image errors can be analyzed with CBCT images, which can reduce the inlfuence of set-up errors caused by image overlapping of 2D images.

  13. Comparison of DP3 Signals Evoked by Comfortable 3D Images and 2D Images — an Event-Related Potential Study using an Oddball Task

    Science.gov (United States)

    Ye, Peng; Wu, Xiang; Gao, Dingguo; Liang, Haowen; Wang, Jiahui; Deng, Shaozhi; Xu, Ningsheng; She, Juncong; Chen, Jun

    2017-02-01

    The horizontal binocular disparity is a critical factor for the visual fatigue induced by watching stereoscopic TVs. Stereoscopic images that possess the disparity within the ‘comfort zones’ and remain still in the depth direction are considered comfortable to the viewers as 2D images. However, the difference in brain activities between processing such comfortable stereoscopic images and 2D images is still less studied. The DP3 (differential P3) signal refers to an event-related potential (ERP) component indicating attentional processes, which is typically evoked by odd target stimuli among standard stimuli in an oddball task. The present study found that the DP3 signal elicited by the comfortable 3D images exhibits the delayed peak latency and enhanced peak amplitude over the anterior and central scalp regions compared to the 2D images. The finding suggests that compared to the processing of the 2D images, more attentional resources are involved in the processing of the stereoscopic images even though they are subjectively comfortable.

  14. Comparison of DP3 Signals Evoked by Comfortable 3D Images and 2D Images — an Event-Related Potential Study using an Oddball Task

    Science.gov (United States)

    Ye, Peng; Wu, Xiang; Gao, Dingguo; Liang, Haowen; Wang, Jiahui; Deng, Shaozhi; Xu, Ningsheng; She, Juncong; Chen, Jun

    2017-01-01

    The horizontal binocular disparity is a critical factor for the visual fatigue induced by watching stereoscopic TVs. Stereoscopic images that possess the disparity within the ‘comfort zones’ and remain still in the depth direction are considered comfortable to the viewers as 2D images. However, the difference in brain activities between processing such comfortable stereoscopic images and 2D images is still less studied. The DP3 (differential P3) signal refers to an event-related potential (ERP) component indicating attentional processes, which is typically evoked by odd target stimuli among standard stimuli in an oddball task. The present study found that the DP3 signal elicited by the comfortable 3D images exhibits the delayed peak latency and enhanced peak amplitude over the anterior and central scalp regions compared to the 2D images. The finding suggests that compared to the processing of the 2D images, more attentional resources are involved in the processing of the stereoscopic images even though they are subjectively comfortable. PMID:28225044

  15. Evaluation of image uniformity in diagnostic magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Ogura, Akio [Kyoto City Hospital (Japan); Inoue, Hiroshi; Higashida, Mitsuji; Yamazaki, Masaru; Uto, Tomoyuki

    1997-12-01

    Image uniformity refers to the ability of the MR imaging system to produce a constant signal response throughout the scanned volume when the object being imaged has homogeneous MR characteristics. To facilitate the determination of image uniformity in diagnostic magnetic resonance images, reports such as the NEMA Standard and AAPM report have been issued. However, these methods of evaluation are impractical in cases such as the day-to-day quality control of the machine or comparisons between the different MR systems, because these methods affect the signal-to-noise ratio (SNR) and create problems by displaying nonuniformity locations. Therefore, we present a new method for evaluating uniformity, called the test segment method. The influence of SNR on the NEMA test and the segment method were examined. In addition, the results of the two methods were compared for certain nonuniformity conditions. Results showed that the segment method did not affect SNR and provided good display of nonuniformity. (author)

  16. Adaptive clutter filter in 2-D color flow imaging based on in vivo I/Q signal.

    Science.gov (United States)

    Zhou, Xiaoming; Zhang, Congyao; Liu, Dong C

    2014-01-01

    Color flow imaging has been well applied in clinical diagnosis. For the high quality color flow images, clutter filter is important to separate the Doppler signals from blood and tissue. Traditional clutter filters, such as finite impulse response, infinite impulse response and regression filters, were applied, which are based on the hypothesis that the clutter signal is stationary or tissue moves slowly. However, in realistic clinic color flow imaging, the signals are non-stationary signals because of accelerated moving tissue. For most related papers, simulated RF signals are widely used without in vivo I/Q signal. Hence, in this paper, adaptive polynomial regression filter, which is down mixing with instantaneous clutter frequency, was proposed based on in vivo carotid I/Q signal in realistic color flow imaging. To get the best performance, the optimal polynomial order of polynomial regression filter and the optimal polynomial order for estimation of instantaneous clutter frequency respectively were confirmed. Finally, compared with the mean blood velocity and quality of 2-D color flow image, the experiment results show that adaptive polynomial regression filter, which is down mixing with instantaneous clutter frequency, can significantly enhance the mean blood velocity and get high quality 2-D color flow image.

  17. Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

    Science.gov (United States)

    Fieselmann, Andreas; Steinbrener, Jan; Jerebko, Anna K.; Voigt, Johannes M.; Scholz, Rosemarie; Ritschl, Ludwig; Mertelmeier, Thomas

    2016-03-01

    In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D cone-beam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

  18. An Automatic Framework for Segmentation and Digital Inpainting of 2D Frontal Face Images

    NARCIS (Netherlands)

    Sobiecki, A.; Giraldi, G. A.; Neves, L. A. P.; Thomaz, C. E.

    2012-01-01

    Nowadays applications that use face images as input for people identification have been very common. In general, the input image must be preprocessed in order to fit some normalization and quality criteria. In this paper, we propose a computational framework composed of digital image quality

  19. Estimation of the Lateral Ventricles Volumes from a 2D Image and Its Relationship with Cerebrospinal Fluid Flow

    Directory of Open Access Journals (Sweden)

    Chaarani Bader

    2013-01-01

    Full Text Available Purpose. This work suggests a fast estimation method of the lateral ventricles volume from a 2D image and then determines if this volume is correlated with the cerebrospinal fluid flow at the aqueductal and cerebral levels in neurodegenerative diseases. Materials and Methods. FForty-five elderly patients suffering from Alzheimer’s disease (19, normal pressure hydrocephalus (13, and vascular dementia (13 were involved and underwent anatomical and phase contrast MRI scans. Lateral ventricles and stroke volumes were assessed on anatomical and phase contrast scans, respectively. A common reference plane was used to calculate the lateral ventricles’ area on 2D images. Results. The largest volumes were observed in hydrocephalus patients. The linear regression between volumes and areas was computed, and a strong positive correlation was detected (R2=0.9. A derived equation was determined to represent the volumes for any given area. On the other hand, no significant correlations were detected between ventricles and stroke volumes (R2≤0.15. Conclusion. Lateral ventricles volumes are significantly proportional to the 2D reference section area and could be used for patients’ follow-up even if 3D images are unavailable. The cerebrospinal fluid fluctuations in brain disorders may depend on many physiological parameters other than the ventricular morphology.

  20. Calibration model of a dual gain flat panel detector for 2D and 3D x-ray imaging.

    Science.gov (United States)

    Schmidgunst, C; Ritter, D; Lang, E

    2007-09-01

    The continuing research and further development in flat panel detector technology have led to its integration into more and more medical x-ray systems for two-dimensional (2D) and three-dimensional (3D) imaging, such as fixed or mobile C arms. Besides the obvious advantages of flat panel detectors, like the slim design and the resulting optimum accessibility to the patient, their success is primarily a product of the image quality that can be achieved. The benefits in the physical and performance-related features as opposed to conventional image intensifier systems, (e.g., distortion-free reproduction of imaging information or almost linear signal response over a large dynamic range) can be fully exploited, however, only if the raw detector images are correctly calibrated and postprocessed. Previous procedures for processing raw data contain idealizations that, in the real world, lead to artifacts or losses in image quality. Thus, for example, temperature dependencies or changes in beam geometry, as can occur with mobile C arm systems, have not been taken into account up to this time. Additionally, adverse characteristics such as image lag or aging effects have to be compensated to attain the best possible image quality. In this article a procedure is presented that takes into account the important dependencies of the individual pixel sensitivity of flat panel detectors used in 2D or 3D imaging and simultaneously minimizes the work required for an extensive recalibration. It is suitable for conventional detectors with only one gain mode as well as for the detectors specially developed for 3D imaging with dual gain read-out technology.

  1. Estimating elastic moduli of rocks from thin sections: Digital rock study of 3D properties from 2D images

    Science.gov (United States)

    Saxena, Nishank; Mavko, Gary

    2016-03-01

    Estimation of elastic rock moduli using 2D plane strain computations from thin sections has several numerical and analytical advantages over using 3D rock images, including faster computation, smaller memory requirements, and the availability of cheap thin sections. These advantages, however, must be weighed against the estimation accuracy of 3D rock properties from thin sections. We present a new method for predicting elastic properties of natural rocks using thin sections. Our method is based on a simple power-law transform that correlates computed 2D thin section moduli and the corresponding 3D rock moduli. The validity of this transform is established using a dataset comprised of FEM-computed elastic moduli of rock samples from various geologic formations, including Fontainebleau sandstone, Berea sandstone, Bituminous sand, and Grossmont carbonate. We note that using the power-law transform with a power-law coefficient between 0.4-0.6 contains 2D moduli to 3D moduli transformations for all rocks that are considered in this study. We also find that reliable estimates of P-wave (Vp) and S-wave velocity (Vs) trends can be obtained using 2D thin sections.

  2. 基于互信息的2D-3D医学图像配准%2D-3D Medical Image Registration Based on Mutual Information

    Institute of Scientific and Technical Information of China (English)

    梁玮; 鲍旭东; 罗立民

    2004-01-01

    介绍一种基于互信息的2D-3D医学图像配准方法,将此方法用于X线透射图(由DRR模拟)与CT体数据的配准,对具体实现方法进行了探讨,用数据采样和灰度级压缩的方法对体数据进行预处理,通过改变平行光入射角度,计算不同方向的DRR图像,用互信息方法配准DRR图像,得到了较好的2D-3D图像配准效果.

  3. Content-based retrieval based on binary vectors for 2-D medical images

    Institute of Scientific and Technical Information of China (English)

    龚鹏; 邹亚东; 洪海

    2003-01-01

    In medical research and clinical diagnosis, automated or computer-assisted classification and retrieval methods are highly desirable to offset the high cost of manual classification and manipulation by medical experts. To facilitate the decision-making in the health-care and the related areas, in this paper, a two-step content-based medical image retrieval algorithm is proposed. Firstly, in the preprocessing step, the image segmentation is performed to distinguish image objects, and on the basis of the ...

  4. Soft-tissues Image Processing: Comparison of Traditional Segmentation Methods with 2D active Contour Methods

    Science.gov (United States)

    Mikulka, J.; Gescheidtova, E.; Bartusek, K.

    2012-01-01

    The paper deals with modern methods of image processing, especially image segmentation, classification and evaluation of parameters. It focuses primarily on processing medical images of soft tissues obtained by magnetic resonance tomography (MR). It is easy to describe edges of the sought objects using segmented images. The edges found can be useful for further processing of monitored object such as calculating the perimeter, surface and volume evaluation or even three-dimensional shape reconstruction. The proposed solutions can be used for the classification of healthy/unhealthy tissues in MR or other imaging. Application examples of the proposed segmentation methods are shown. Research in the area of image segmentation focuses on methods based on solving partial differential equations. This is a modern method for image processing, often called the active contour method. It is of great advantage in the segmentation of real images degraded by noise with fuzzy edges and transitions between objects. In the paper, results of the segmentation of medical images by the active contour method are compared with results of the segmentation by other existing methods. Experimental applications which demonstrate the very good properties of the active contour method are given.

  5. 2D and 3D MALDI-imaging: conceptual strategies for visualization and data mining.

    Science.gov (United States)

    Thiele, Herbert; Heldmann, Stefan; Trede, Dennis; Strehlow, Jan; Wirtz, Stefan; Dreher, Wolfgang; Berger, Judith; Oetjen, Janina; Kobarg, Jan Hendrik; Fischer, Bernd; Maass, Peter

    2014-01-01

    3D imaging has a significant impact on many challenges in life sciences, because biology is a 3-dimensional phenomenon. Current 3D imaging-technologies (various types MRI, PET, SPECT) are labeled, i.e. they trace the localization of a specific compound in the body. In contrast, 3D MALDI mass spectrometry-imaging (MALDI-MSI) is a label-free method imaging the spatial distribution of molecular compounds. It complements 3D imaging labeled methods, immunohistochemistry, and genetics-based methods. However, 3D MALDI-MSI cannot tap its full potential due to the lack of statistical methods for analysis and interpretation of large and complex 3D datasets. To overcome this, we established a complete and robust 3D MALDI-MSI pipeline combined with efficient computational data analysis methods for 3D edge preserving image denoising, 3D spatial segmentation as well as finding colocalized m/z values, which will be reviewed here in detail. Furthermore, we explain, why the integration and correlation of the MALDI imaging data with other imaging modalities allows to enhance the interpretation of the molecular data and provides visualization of molecular patterns that may otherwise not be apparent. Therefore, a 3D data acquisition workflow is described generating a set of 3 different dimensional images representing the same anatomies. First, an in-vitro MRI measurement is performed which results in a three-dimensional image modality representing the 3D structure of the measured object. After sectioning the 3D object into N consecutive slices, all N slices are scanned using an optical digital scanner, enabling for performing the MS measurements. Scanning the individual sections results into low-resolution images, which define the base coordinate system for the whole pipeline. The scanned images conclude the information from the spatial (MRI) and the mass spectrometric (MALDI-MSI) dimension and are used for the spatial three-dimensional reconstruction of the object performed by image

  6. 2D and 3D imaging resolution trade-offs in quantifying pore throats for prediction of permeability

    Energy Technology Data Exchange (ETDEWEB)

    Beckingham, Lauren E.; Peters, Catherine A.; Um, Wooyong; Jones, Keith W.; Lindquist, W.Brent

    2013-09-03

    Although the impact of subsurface geochemical reactions on porosity is relatively well understood, changes in permeability remain difficult to estimate. In this work, pore-network modeling was used to predict permeability based on pore- and pore-throat size distributions determined from analysis of 2D scanning electron microscopy (SEM) images of thin sections and 3D X-ray computed microtomography (CMT) data. The analyzed specimens were a Viking sandstone sample from the Alberta sedimentary basin and an experimental column of reacted Hanford sediments. For the column, a decrease in permeability due to mineral precipitation was estimated, but the permeability estimates were dependent on imaging technique and resolution. X-ray CT imaging has the advantage of reconstructing a 3D pore network while 2D SEM imaging can easily analyze sub-grain and intragranular variations in mineralogy. Pore network models informed by analyses of 2D and 3D images at comparable resolutions produced permeability esti- mates with relatively good agreement. Large discrepancies in predicted permeabilities resulted from small variations in image resolution. Images with resolutions 0.4 to 4 lm predicted permeabilities differ- ing by orders of magnitude. While lower-resolution scans can analyze larger specimens, small pore throats may be missed due to resolution limitations, which in turn overestimates permeability in a pore-network model in which pore-to-pore conductances are statistically assigned. Conversely, high-res- olution scans are capable of capturing small pore throats, but if they are not actually flow-conducting predicted permeabilities will be below expected values. In addition, permeability is underestimated due to misinterpreting surface-roughness features as small pore throats. Comparison of permeability pre- dictions with expected and measured permeability values showed that the largest discrepancies resulted from the highest resolution images and the best predictions of

  7. Registration of 2D C-Arm and 3D CT Images for a C-Arm Image-Assisted Navigation System for Spinal Surgery

    Directory of Open Access Journals (Sweden)

    Chih-Ju Chang

    2015-01-01

    Full Text Available C-Arm image-assisted surgical navigation system has been broadly applied to spinal surgery. However, accurate path planning on the C-Arm AP-view image is difficult. This research studies 2D-3D image registration methods to obtain the optimum transformation matrix between C-Arm and CT image frames. Through the transformation matrix, the surgical path planned on preoperative CT images can be transformed and displayed on the C-Arm images for surgical guidance. The positions of surgical instruments will also be displayed on both CT and C-Arm in the real time. Five similarity measure methods of 2D-3D image registration including Normalized Cross-Correlation, Gradient Correlation, Pattern Intensity, Gradient Difference Correlation, and Mutual Information combined with three optimization methods including Powell’s method, Downhill simplex algorithm, and genetic algorithm are applied to evaluate their performance in converge range, efficiency, and accuracy. Experimental results show that the combination of Normalized Cross-Correlation measure method with Downhill simplex algorithm obtains maximum correlation and similarity in C-Arm and Digital Reconstructed Radiograph (DRR images. Spine saw bones are used in the experiment to evaluate 2D-3D image registration accuracy. The average error in displacement is 0.22 mm. The success rate is approximately 90% and average registration time takes 16 seconds.

  8. Enhanced 2D-image upconversion using solid-state lasers

    DEFF Research Database (Denmark)

    Pedersen, Christian; Karamehmedovic, Emir; Dam, Jeppe Seidelin

    2009-01-01

    Based on enhanced upconversion, we demonstrate a highly efficient method for converting a full image from one part of the electromagnetic spectrum into a new desired wavelength region. By illuminating a metal transmission mask with a 765 nm Gaussian beam to create an image and subsequently focusing...

  9. Fast Ion Induced Shearing of 2D Alfven Eigenmodes Measured by Electron Cyclotron Emission Imaging

    NARCIS (Netherlands)

    Tobias, B. J.; Classen, I.G.J.; Domier, C.W.; Heidbrink, W. W.; N C Luhmann Jr.,; Nazikian, R.; Park, H. K.; Spong, D. A.; VanZeeland, M. A.

    2011-01-01

    Two-dimensional images of electron temperature perturbations are obtained with electron cyclotron emission imaging (ECEI) on the DIII-D tokamak and compared to Alfven eigenmode structures obtained by numerical modeling using both ideal MHD and hybrid MHD-gyrofluid codes. While many features of the o

  10. Clinical application of 2D-FIESTA cine imaging in the treatment of lumbar disc herniation%腰椎间盘突出症2D-FIESTA Cine成像的临床应用

    Institute of Scientific and Technical Information of China (English)

    刘春红; 杜铁桥; 董杰; 李海梅; 张宇

    2011-01-01

    Objective To investigate the clinical application of 2D- fiesta cine imaging in the treatment of lumbar disc herniation.Methods 18 patients with lumbar disc hemiation underwent T1- and T2-weighted Spin-Echo (SE) MR images, fat saturation FSE T2WI, FS-FSE T2WI ( FSE T2WI) cine and Fast Imaging Employing Steady state Acquisition (2D-FIESTA) cine MR imaging.We retrospectively analysed the presentations on 2D-FIESTA cine images of all patients who were confirmed to have lumbar disc herniation through surgical histological examination or follow-up,and compare the scanning time with that of other general sequencing MR imaging.Results 18 patients had 33 affected discs.They were present with low signal on SE TiWI, but medium signal on FS-FSE T2WI, FSE T2WI and FIESTA.Except for showing the condition of the herniated disc, 2D-FIESTA cine could also clearly show the compressed spine nerves.The scanning time of 2D-FIESTA cine was only 13.3% of that of T2WI, and 17.9% of that of T1WI.Thus it was significant that the scanning time of 2D-FIESTA cine was shorter than conventional MRI scan.Conclusions 2D-FIESTA cine can provide valuable information regarding lumbar disc hemiation.It is an effective supplement for conventional MRI.%目的 评价2D-FIESTA cine成像在腰椎间盘突出症中的临床应用价值.方法 18例腰椎间盘突出症患者分别行矢状位SE T1WI,快速SE(FSE)T2WI,脂肪抑制FSE T2WI(fat saturation FSE T2WI,FS-FSE T2WI)及2D-FIESTA(fast imaging employing steady-state acquisition,FIESTA)cine.回顾性分析18例经手术病理或随访证实腰椎间盘突出症的2D-FIESTA cine表现,并与其他常规序列的MR扫描时间进行比较.结果 18例腰椎间盘突出症患者,共33个椎间盘受累.在SE T1WI上,病变均呈低信号,FS-FSE T2WI、FSE T2WI和FIESTA呈中等信号或低信号.2D-FIESTA cine除可动态显示突出椎间盘的情况,并可清楚显示受压的脊神经.2D-FIESTA的扫描时间仅为T2WI的13.3%;为T1WI的17.9%.2D

  11. Development of a 2D silicon strip detector system for mammographic imaging using particle physics technology

    CERN Document Server

    Royle, G J; Speller, R D; Hall, G; Iles, G; Raymond, M; Corrin, E; Stelt, P F; Manthos, N; Triantis, F A

    2002-01-01

    2D silicon strip sensors using particle physics readout technology have been evaluated as mammographic detectors. Two different versions of the APV series of front-end electronics were used that provided different noise levels. The sensors were evaluated using a typical mammography X-ray spectrum. The spatial resolution was evaluated using line pair test patterns and the modulation transfer function (MTF) was measured using the Edge Response Function. Low contrast performance was measured using the TOR(MAX) test object. Limiting spatial resolution of 52 mu m was obtained and an MTF value of 0.1 at 16 lp/mm. The low contrast performance was estimated from 250, 500 mu m and 6 mm diameter objects and was found to be 11.5%, 7% and better than 3.8%, respectively.

  12. Improving object detection in 2D images using a 3D world model

    Science.gov (United States)

    Viggh, Herbert E. M.; Cho, Peter L.; Armstrong-Crews, Nicholas; Nam, Myra; Shah, Danelle C.; Brown, Geoffrey E.

    2014-05-01

    A mobile robot operating in a netcentric environment can utilize offboard resources on the network to improve its local perception. One such offboard resource is a world model built and maintained by other sensor systems. In this paper we present results from research into improving the performance of Deformable Parts Model object detection algorithms by using an offboard 3D world model. Experiments were run for detecting both people and cars in 2D photographs taken in an urban environment. After generating candidate object detections, a 3D world model built from airborne Light Detection and Ranging (LIDAR) and aerial photographs was used to filter out false alarm using several types of geometric reasoning. Comparison of the baseline detection performance to the performance after false alarm filtering showed a significant decrease in false alarms for a given probability of detection.

  13. Fast Plane Wave 2-D Vector Flow Imaging Using Transverse Oscillation and Directional Beamforming

    DEFF Research Database (Denmark)

    Jensen, Jonas; Villagómez Hoyos, Carlos Armando; Stuart, Matthias Bo

    2017-01-01

    Several techniques can estimate the 2-D velocity vector in ultrasound. Directional beamforming (DB) estimates blood flow velocities with a higher precision and accuracy than transverse oscillation (TO), but at the cost of a high beamforming load when estimating the flow angle. In this paper......, it is proposed to use TO to estimate an initial flow angle, which is then refined in a DB step. Velocity magnitude is estimated along the flow direction using cross-correlation. It is shown that the suggested TO-DB method can improve the performance of velocity estimates compared to TO, and with a beamforming...... but within 4% for TO-DB. The same trends are observed in measurements although with a slightly larger bias. Simulations of realistic flow in a carotid bifurcation model provide visualization of complex flow, and the spread of velocity magnitude estimates is 7.1 cm/s for TO-DB, while it is 11.8 cm/s using...

  14. Interpolated compressed sensing for 2D multiple slice fast MR imaging.

    Directory of Open Access Journals (Sweden)

    Yong Pang

    Full Text Available Sparse MRI has been introduced to reduce the acquisition time and raw data size by undersampling the k-space data. However, the image quality, particularly the contrast to noise ratio (CNR, decreases with the undersampling rate. In this work, we proposed an interpolated Compressed Sensing (iCS method to further enhance the imaging speed or reduce data size without significant sacrifice of image quality and CNR for multi-slice two-dimensional sparse MR imaging in humans. This method utilizes the k-space data of the neighboring slice in the multi-slice acquisition. The missing k-space data of a highly undersampled slice are estimated by using the raw data of its neighboring slice multiplied by a weighting function generated from low resolution full k-space reference images. In-vivo MR imaging in human feet has been used to investigate the feasibility and the performance of the proposed iCS method. The results show that by using the proposed iCS reconstruction method, the average image error can be reduced and the average CNR can be improved, compared with the conventional sparse MRI reconstruction at the same undersampling rate.

  15. OPTIMIZATION OF DIAGNOSTIC IMAGING IN BREAST CANCER

    Directory of Open Access Journals (Sweden)

    S. A. Velichko

    2015-01-01

    Full Text Available The paper presents the results of breast imaging for 47200 women. Breast cancer was detected in 862 (1.9% patients, fibroadenoma in 1267 (2.7% patients and isolated breast cysts in 1162 (2.4% patients. Different types of fibrocystic breast disease (adenosis, diffuse fibrocystic changes, local fibrosis and others were observed in 60.1% of women. Problems of breast cancer visualization during mammography, characterized by the appearance of fibrocystic mastopathy (sclerosing adenosis, fibrous bands along the ducts have been analyzed. Data on the development of diagnostic algorithms including the modern techniques for ultrasound and interventional radiology aimed at detecting early breast cancer have been presented.  

  16. Assessing 3D tunnel position in ACL reconstruction using a novel single image 3D-2D registration

    Science.gov (United States)

    Kang, X.; Yau, W. P.; Otake, Y.; Cheung, P. Y. S.; Hu, Y.; Taylor, R. H.

    2012-02-01

    The routinely used procedure for evaluating tunnel positions following anterior cruciate ligament (ACL) reconstructions based on standard X-ray images is known to pose difficulties in terms of obtaining accurate measures, especially in providing three-dimensional tunnel positions. This is largely due to the variability in individual knee joint pose relative to X-ray plates. Accurate results were reported using postoperative CT. However, its extensive usage in clinical routine is hampered by its major requirement of having CT scans of individual patients, which is not available for most ACL reconstructions. These difficulties are addressed through the proposed method, which aligns a knee model to X-ray images using our novel single-image 3D-2D registration method and then estimates the 3D tunnel position. In the proposed method, the alignment is achieved by using a novel contour-based 3D-2D registration method wherein image contours are treated as a set of oriented points. However, instead of using some form of orientation weighting function and multiplying it with a distance function, we formulate the 3D-2D registration as a probability density estimation using a mixture of von Mises-Fisher-Gaussian (vMFG) distributions and solve it through an expectation maximization (EM) algorithm. Compared with the ground-truth established from postoperative CT, our registration method in an experiment using a plastic phantom showed accurate results with errors of (-0.43°+/-1.19°, 0.45°+/-2.17°, 0.23°+/-1.05°) and (0.03+/-0.55, -0.03+/-0.54, -2.73+/-1.64) mm. As for the entry point of the ACL tunnel, one of the key measurements, it was obtained with high accuracy of 0.53+/-0.30 mm distance errors.

  17. Known-component 3D-2D registration for image guidance and quality assurance in spine surgery pedicle screw placement

    Science.gov (United States)

    Uneri, A.; Stayman, J. W.; De Silva, T.; Wang, A. S.; Kleinszig, G.; Vogt, S.; Khanna, A. J.; Wolinsky, J.-P.; Gokaslan, Z. L.; Siewerdsen, J. H.

    2015-03-01

    Purpose. To extend the functionality of radiographic / fluoroscopic imaging systems already within standard spine surgery workflow to: 1) provide guidance of surgical device analogous to an external tracking system; and 2) provide intraoperative quality assurance (QA) of the surgical product. Methods. Using fast, robust 3D-2D registration in combination with 3D models of known components (surgical devices), the 3D pose determination was solved to relate known components to 2D projection images and 3D preoperative CT in near-real-time. Exact and parametric models of the components were used as input to the algorithm to evaluate the effects of model fidelity. The proposed algorithm employs the covariance matrix adaptation evolution strategy (CMA-ES) to maximize gradient correlation (GC) between measured projections and simulated forward projections of components. Geometric accuracy was evaluated in a spine phantom in terms of target registration error at the tool tip (TREx), and angular deviation (TREΦ) from planned trajectory. Results. Transpedicle surgical devices (probe tool and spine screws) were successfully guided with TREx30° (easily accommodated on a mobile C-arm). QA of the surgical product based on 3D-2D registration demonstrated the detection of pedicle screw breach with TRExConclusions. 3D-2D registration combined with 3D models of known surgical components provides a novel method for near-real-time guidance and quality assurance using a mobile C-arm without external trackers or fiducial markers. Ongoing work includes determination of optimal views based on component shape and trajectory, improved robustness to anatomical deformation, and expanded preclinical testing in spine and intracranial surgeries.

  18. Image Compression Technique Based on Discrete 2-D wavelet transforms with Arithmetic Coding

    Directory of Open Access Journals (Sweden)

    Deepika Sunoriya

    2012-06-01

    Full Text Available Digital Images play a very important role fordescribing the detailed information about man,money, machine almost in every field. The variousprocesses of digitizing the images to obtain it in thebest quality for the more clear and accurateinformation leads to the requirement of morestorage space and better storage and accessingmechanism in the form of hardware or software. Inthis paper we apply a technique for imagecompression. Our proposed approach is thecombination of several approaches to make thecompression better than the previous usedapproach. In this technique we first apply walshtransformation. Split all DC values form eachtransformed block 8x8.After that we applyarithmetic coding for compress an image. In thispaper we also present a brief survey on severalImage Compression Techniques.

  19. Performance Evaluation of 2D Adaptive Bilateral Filter For Removal of Noise From Robust Images

    National Research Council Canada - National Science Library

    B.Sridhar; Dr.K.V.V.S.Reddy

    2013-01-01

    .... The variance of range filter can also be adaptive. The filter is applied to improve the sharpens of a gray level and color image by increasing the slope of the edges without producing overshoot or undershoots...

  20. Registration of 2D to 3D joint images using phase-based mutual information

    Science.gov (United States)

    Dalvi, Rupin; Abugharbieh, Rafeef; Pickering, Mark; Scarvell, Jennie; Smith, Paul

    2007-03-01

    Registration of two dimensional to three dimensional orthopaedic medical image data has important applications particularly in the area of image guided surgery and sports medicine. Fluoroscopy to computer tomography (CT) registration is an important case, wherein digitally reconstructed radiographs derived from the CT data are registered to the fluoroscopy data. Traditional registration metrics such as intensity-based mutual information (MI) typically work well but often suffer from gross misregistration errors when the image to be registered contains a partial view of the anatomy visible in the target image. Phase-based MI provides a robust alternative similarity measure which, in addition to possessing the general robustness and noise immunity that MI provides, also employs local phase information in the registration process which makes it less susceptible to the aforementioned errors. In this paper, we propose using the complex wavelet transform for computing image phase information and incorporating that into a phase-based MI measure for image registration. Tests on a CT volume and 6 fluoroscopy images of the knee are presented. The femur and the tibia in the CT volume were individually registered to the fluoroscopy images using intensity-based MI, gradient-based MI and phase-based MI. Errors in the coordinates of fiducials present in the bone structures were used to assess the accuracy of the different registration schemes. Quantitative results demonstrate that the performance of intensity-based MI was the worst. Gradient-based MI performed slightly better, while phase-based MI results were the best consistently producing the lowest errors.

  1. Integrated circuits for volumetric ultrasound imaging with 2-D CMUT arrays.

    Science.gov (United States)

    Bhuyan, Anshuman; Choe, Jung Woo; Lee, Byung Chul; Wygant, Ira O; Nikoozadeh, Amin; Oralkan, Ömer; Khuri-Yakub, Butrus T

    2013-12-01

    Real-time volumetric ultrasound imaging systems require transmit and receive circuitry to generate ultrasound beams and process received echo signals. The complexity of building such a system is high due to requirement of the front-end electronics needing to be very close to the transducer. A large number of elements also need to be interfaced to the back-end system and image processing of a large dataset could affect the imaging volume rate. In this work, we present a 3-D imaging system using capacitive micromachined ultrasonic transducer (CMUT) technology that addresses many of the challenges in building such a system. We demonstrate two approaches in integrating the transducer and the front-end electronics. The transducer is a 5-MHz CMUT array with an 8 mm × 8 mm aperture size. The aperture consists of 1024 elements (32 × 32) with an element pitch of 250 μm. An integrated circuit (IC) consists of a transmit beamformer and receive circuitry to improve the noise performance of the overall system. The assembly was interfaced with an FPGA and a back-end system (comprising of a data acquisition system and PC). The FPGA provided the digital I/O signals for the IC and the back-end system was used to process the received RF echo data (from the IC) and reconstruct the volume image using a phased array imaging approach. Imaging experiments were performed using wire and spring targets, a ventricle model and a human prostrate. Real-time volumetric images were captured at 5 volumes per second and are presented in this paper.

  2. 2D image registration using focused mutual information for application in dentistry.

    Science.gov (United States)

    Jacquet, W; Nyssen, E; Bottenberg, P; Truyen, B; de Groen, P

    2009-06-01

    Spatial alignment of image data is a common task in computer vision and medical imaging. This should preferentially be done with minimal intervention of an operator. Similarity measures with origin in the information theory such as mutual information (MI) have proven to be robust registration criteria for this purpose. Intra-oral radiographs can be considered images of piecewise rigid objects. Teeth and jaws are rigid but can be displaced with respect to each other. Therefore MI criteria combined with affine deformations tend to fail, when teeth and jaws move with respect to each other between image acquisitions. In this paper, we consider a focused weighing of pixels in the reference image. The resulting criterion, focused mutual information (FMI) is an adequate tool for the registration of rigid parts of a scene. We also show that the use of FMI is more robust for the subtraction of lateral radiographs of teeth, than MI confined to a region of interest. Furthermore, the criterion allows the follow-up of small carious lesions when upper and lower jaw moved between the acquisition of test and reference image.

  3. Diagnostic Value of 64-slice CTA in Detection of Intracranial Aneurysm in Patients with SAH and Comparison of the CTA Results with 2D-DSA and Intraoperative Findings

    Directory of Open Access Journals (Sweden)

    Elif Ergun

    2011-03-01

    Full Text Available Objective: To prospectively evaluate the diagnostic value of 64-slice CTA in detecting intracranial aneurysms and to compare it with 2D-DSA and/or intra-operative findings.Material and Methods: 37 cases with SAH according to unenhanced cranial CT were included in the study. A 64-slice CTA was performed to all cases immediately after the nonenhanced cranial CT. DSA was performed in 24-48 hours following CTA. CT images were reviewed by two radiologists experienced in CT vascular imaging. The DSA reader was the angiographer who performed the DSA. The results of the CTA were compared with the DSA results and/or intraoperative findings in order to determine the diagnostic efficacy of CTA in detecting intracranial aneurysms. Results: Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CTA in detecting aneurysms were 92.8%, 83.3%, 96.2%, 71.4% and 91.2% respectively. The diagnostic value of CTA in detecting intracranial aneurysms was found to be equal to DSA by Mcnemar test. Conclusion: CTA is invaluable in detecting intracranial aneurysms. It may be used as a first line modality in SAH, and DSA may be reserved for patients with negative or equivocal CTA results.

  4. Application and further development of diffusion based 2D chemical imaging techniques in the rhizosphere

    Science.gov (United States)

    Hoefer, Christoph; Santner, Jakob; Borisov, Sergey; Kreuzeder, Andreas; Wenzel, Walter; Puschenreiter, Markus

    2015-04-01

    Two dimensional chemical imaging of root processes refers to novel in situ methods to investigate and map solutes at a high spatial resolution (sub-mm). The visualization of these solutes reveals new insights in soil biogeochemistry and root processes. We derive chemical images by using data from DGT-LA-ICP-MS (Diffusive Gradients in Thin Films and Laser Ablation Inductively Coupled Plasma Mass Spectrometry) and POS (Planar Optode Sensors). Both technologies have shown promising results when applied in aqueous environment but need to be refined and improved for imaging at the soil-plant interface. Co-localized mapping using combined DGT and POS technologies and the development of new gel combinations are in our focus. DGTs are smart and thin (images of the target area are plotted using imaging software. POS are, similar to DGT, thin sensor foils containing a fluorophore coating depending on the target analyte. The measurement principle is based on excitation of the flourophore by a specific wavelength and emission of the fluorophore depending on the presence of the analyte. The emitted signal is captured using optical filters and a DSLR camera. While DGT analysis is destructive, POS measurements can be performed continuously during the application. Both semi-quantitative techniques allow an in situ application to visualize chemical processes directly at the soil-plant interface. Here, we present a summary of results from rhizotron experiments with different plants in metal contaminated and agricultural soils.

  5. A novel image fusion algorithm based on 2D scale-mixing complex wavelet transform and Bayesian MAP estimation for multimodal medical images

    Directory of Open Access Journals (Sweden)

    Abdallah Bengueddoudj

    2017-05-01

    Full Text Available In this paper, we propose a new image fusion algorithm based on two-dimensional Scale-Mixing Complex Wavelet Transform (2D-SMCWT. The fusion of the detail 2D-SMCWT coefficients is performed via a Bayesian Maximum a Posteriori (MAP approach by considering a trivariate statistical model for the local neighboring of 2D-SMCWT coefficients. For the approximation coefficients, a new fusion rule based on the Principal Component Analysis (PCA is applied. We conduct several experiments using three different groups of multimodal medical images to evaluate the performance of the proposed method. The obtained results prove the superiority of the proposed method over the state of the art fusion methods in terms of visual quality and several commonly used metrics. Robustness of the proposed method is further tested against different types of noise. The plots of fusion metrics establish the accuracy of the proposed fusion method.

  6. Robust and highly performant ring detection algorithm for 3d particle tracking using 2d microscope imaging

    CERN Document Server

    Afik, Eldad

    2013-01-01

    Three-dimensional particle tracking is an essential tool in studying dynamics under the microscope, namely, cellular trafficking, bacteria taxis, fluid dynamics in microfluidics devices. The 3d position of a fluorescent particle can be determined using 2d imaging alone, by measuring the diffraction rings generated by an out-of-focus particle, imaged on a single camera. Here I present a ring detection algorithm exhibiting a high detection rate, which is robust to the challenges arising from particles vicinity. It is capable of real time analysis thanks to its high performance and low memory footprint. Many of the algorithmic concepts introduced can be advantageous in other cases, particularly for sparse data. The implementation is based on open-source and cross-platform software packages only, making it easy to distribute and modify. The image analysis algorithm, which is an offspring of the full 3d circle Hough transform, addresses the need to efficiently trace the trajectories of several particles concurrent...

  7. HESSIAN MATRIX BASED SADDLE POINT DETECTION FOR GRANULES SEGMENTALTION IN 2D IMAGE

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Segmenting the touching objects in an image has been remaining as a hot subject due to the problematic complexities,and a vast number of algorithms designed to tackle this issue have come into being since a decade ago.In this paper,a new granule segmentation algorithm is developed using saddle point as the cutting point.The image is binarized and then sequentially eroded to form a gray-scale topographic counterpart,followed by using Hessian matrix computation to search for the saddle point. The segmentation is performed by cutting through the saddle point and along the maximal gradient path on the topographic surface.The results of the algorithm test on the given real images indicate certain superiorities in both the segmenting robustness and execution time to the referenced methods.

  8. One decade of imaging precipitation measurement by 2D-video-distrometer

    Directory of Open Access Journals (Sweden)

    M. Schönhuber

    2007-01-01

    Full Text Available The 2D-Video-Distrometer (2DVD is a ground-based point-monitoring precipitation gauge. From each particle reaching the measuring area front and side contours as well as fall velocity and precise time stamp are recorded. In 1991 the 2DVD development has been started to clarify discrepancies found when comparing weather radar data analyses with literature models. Then being manufactured in a small scale series the first 2DVD delivery took place in 1996, 10 years back from now. An overview on present 2DVD features is given, and it is presented how the instrument was continuously improved in the past ten years. Scientific merits of 2DVD measurements are explained, including drop size readings without upper limit, drop shape and orientation angle information, contours of solid and melting particles, and an independent measurement of particles' fall velocity also in mixed phase events. Plans for a next generation instrument are described, by enhanced user-friendliness the unique data type shall be opened to a wider user community.

  9. Adaptive Filters for 2-D and 3-D Digital Images Processing

    OpenAIRE

    Martišek, Karel

    2012-01-01

    Práce se zabývá adaptivními filtry pro vizualizaci obrazů s vysokým rozlišením. V teoretické části je popsán princip činnosti konfokálního mikroskopu a matematicky korektně zaveden pojem digitální obraz. Pro zpracování obrazů je volen jak frekvenční přístup (s využitím 2-D a 3-D diskrétní Fourierovy transformace a frekvenčních filtrů), tak přístup pomocí digitální geometrie (s využitím adaptivní ekvalizace histogramu s adaptivním okolím). Dále jsou popsány potřebné úpravy pro práci s neideáln...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-01

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

  11. Heterogeneity of Particle Deposition by Pixel Analysis of 2D Gamma Scintigraphy Images.

    Science.gov (United States)

    Bennett, William D; Xie, Miao; Zeman, Kirby; Hurd, Harry; Donaldson, Scott

    2015-06-01

    Heterogeneity of inhaled particle deposition in airways disease may be a sensitive indicator of physiologic changes in the lungs. Using planar gamma scintigraphy, we developed new methods to locate and quantify regions of high (hot) and low (cold) particle deposition in the lungs. Initial deposition and 24 hour retention images were obtained from healthy (n=31) adult subjects and patients with mild cystic fibrosis lung disease (CF) (n=14) following inhalation of radiolabeled particles (Tc99m-sulfur colloid, 5.4 μm MMAD) under controlled breathing conditions. The initial deposition image of the right lung was normalized to (i.e., same median pixel value), and then divided by, a transmission (Tc99m) image in the same individual to obtain a pixel-by-pixel ratio image. Hot spots were defined where pixel values in the deposition image were greater than 2X those of the transmission, and cold spots as pixels where the deposition image was less than 0.5X of the transmission. The number ratio (NR) of the hot and cold pixels to total lung pixels, and the sum ratio (SR) of total counts in hot pixels to total lung counts were compared between healthy and CF subjects. Other traditional measures of regional particle deposition, nC/P and skew of the pixel count histogram distribution, were also compared. The NR of cold spots was greater in mild CF, 0.221±0.047(CF) vs. 0.186±0.038 (healthy) (p<0.005) and was significantly correlated with FEV1 %pred in the patients (R=-0.70). nC/P (central to peripheral count ratio), skew of the count histogram, and hot NR or SR were not different between the healthy and mild CF patients. These methods may provide more sensitive measures of airway function and localization of deposition that might be useful for assessing treatment efficacy in these patients.

  12. Volumetric Synthetic Aperture Imaging with a Piezoelectric 2-D Row-Column Probe

    DEFF Research Database (Denmark)

    Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann

    2016-01-01

    to 32 dB is measured on the beamformed images of a tissue mimicking phantom with attenuation of 0.5 dB cm−1 MHz−1, from the surface of the probe to the penetration depth of 300λ. Measured lateral resolution as Full-Width-at-Half-Maximum (FWHM) is between 4λ and 10λ for 18 % to 65 % of the penetration...... depth from the surface of the probe. The averaged contrast is 13 dB for the same range. The imaging performance assessment results may represent a reference guide for possible applications of such an array in different medical fields...

  13. Implementation of the 2-D Wavelet Transform into FPGA for Image

    Science.gov (United States)

    León, M.; Barba, L.; Vargas, L.; Torres, C. O.

    2011-01-01

    This paper presents a hardware system implementation of the of discrete wavelet transform algoritm in two dimensions for FPGA, using the Daubechies filter family of order 2 (db2). The decomposition algorithm of this transform is designed and simulated with the Hardware Description Language VHDL and is implemented in a programmable logic device (FPGA) XC3S1200E reference, Spartan IIIE family, by Xilinx, take advantage the parallels properties of these gives us and speeds processing that can reach them. The architecture is evaluated using images input of different sizes. This implementation is done with the aim of developing a future images encryption hardware system using wavelet transform for security information.

  14. Fast Ion Induced Shearing of 2D Alfven Eigenmodes Measured by Electron Cyclotron Emission Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, Ben [University of California, Davis; Classen, I.G.J. [FOM Institute for Plasma Physics Rijnhuizen, Nieuwegein, The Netherlands; Domier, C. W. [University of California, Davis; Heidbrink, W. [University of California, Irvine; Luhmann, N.C. [University of California, Davis; Nazikian, Raffi [Princeton Plasma Physics Laboratory (PPPL); Park, H.K. [Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea; Spong, Donald A [ORNL; Van Zeeland, Michael [General Atomics

    2011-01-01

    Two-dimensional images of electron temperature perturbations are obtained with electron cyclotron emission imaging (ECEI) on the DIII-D tokamak and compared to Alfven eigenmode structures obtained by numerical modeling using both ideal MHD and hybrid MHD-gyrofluid codes. While many features of the observations are found to be in excellent agreement with simulations using an ideal MHD code (NOVA), other characteristics distinctly reveal the influence of fast ions on the mode structures. These features are found to be well described by the nonperturbative hybrid MHD-gyrofluid model TAEFL.

  15. Diagnostic imaging in patients with retinitis pigmentosa.

    Science.gov (United States)

    Mitamura, Yoshinori; Mitamura-Aizawa, Sayaka; Nagasawa, Toshihiko; Katome, Takashi; Eguchi, Hiroshi; Naito, Takeshi

    2012-01-01

    Retinitis pigmentosa (RP) is a progressive inherited retinal disease, and patients with RP have reduced visual function caused by a degeneration of the photoreceptors and retinal pigment epithelium (RPE). At the end stage of RP, the degeneration of the photoreceptors in the fovea reduces central vision, and RP is one of the main causes of acquired blindness in developed countries. Therefore, morphological and functional assessments of the photoreceptors in the macula area can be useful in estimating the residual retinal function in RP patients. Optical coherence tomography (OCT) is a well-established method of examining the retinal architecture in situ. The photoreceptor inner/outer segment (IS/OS) junction is observed as a distinct, highly reflective line by OCT. The presence of the IS/OS junction in the OCT images is essential for normal visual function. Fundus autofluorescence (FAF) results from the accumulation of lipofuscin in the RPE cells and has been used to investigate RPE and retinal function. More than one-half of RP patients have an abnormally high density parafoveal FAF ring (AF ring). The AF ring represents the border between functional and dysfunctional retina. In this review, we shall summarize recent progress on diagnostic imaging in eyes with RP.

  16. A Practical Deconvolution Computation Algorithm to Extract 1D Spectra from 2D Images of Optical Fiber Spectroscopy

    CERN Document Server

    Li, Guangwei; Bai, Zhongrui

    2015-01-01

    Bolton and Schlegel presented a promising deconvolution method to extract 1D spectra from a 2D optical fiber spectral CCD image. The method could eliminate the PSF difference between fibers, extract spectra to the photo noise level, as well as improve the resolution. But the method is limited by its huge computation requirement and thus cannot be implemented in actual data reduction. In this article, we develop a practical computation method to solve the computation problem. The new computation method can deconvolve a 2D fiber spectral image of any size with actual PSFs, which may vary with positions. Our method does not require large amounts of memory and can extract a 4k multi 4k noise-free CCD image with 250 fibers in 2 hr. To make our method more practical, we further consider the influence of noise, which is thought to be an intrinsic illposed problem in deconvolution algorithms. We modify our method with a Tikhonov regularization item to depress the method induced noise. Compared with the results of tra...

  17. Assessment of array scintillation detector for follicle thyroid 2-D image acquisition using Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Carlos Borges da; Santanna, Claudio Reis de [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mails: borges@ien.gov.br; santanna@ien.gov.br; Braz, Delson [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mail: delson@lin.ufrj.br; Carvalho, Denise Pires de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho. Lab. de Fisiologia Endocrina]. E-mail: dencarv@ufrj.br

    2007-07-01

    This work presents an innovative study to find out the adequate scintillation inorganic detector array to be used coupled to a specific light photo sensor, a charge coupled device (CCD), through a fiber optic plate. The goal is to choose the type of detector that fits a 2-dimensional imaging acquisition of a cell thyroid tissue application with high resolution and detection efficiency in order to map a follicle image using gamma radiation emission. A point or volumetric source - detector simulation by using a MCNP4B general code, considering different source energies, detector materials and geometry including pixel sizes and reflector types was performed. In this study, simulations were performed for 7 x 7 and 127 x 127 arrays using CsI(Tl) and BGO scintillation crystals with pixel size ranging from 1 x 1 cm{sup 2} to 10 x 10 {mu}m{sup 2} and radiation thickness ranging from 1 mm to 10 mm. The effect of all these parameters was investigated to find the best source-detector system that result in an image with the best contrast details. The results showed that it is possible to design a specific imaging system that allows searching for in-vitro studies, specifically in radiobiology applied to endocrine physiology. (author)

  18. Injectable Colloidal Gold for Use in Intrafractional 2D Image-Guided Radiation Therapy

    DEFF Research Database (Denmark)

    Jølck, Rasmus Irming; Rydhog, Jonas S.; Christensen, Anders Nymark

    2015-01-01

    In the western world, approximately 50% of all cancer patients receive radiotherapy alone or in combination with surgery or chemotherapy. Image-guided radiotherapy (IGRT) has in recent years been introduced to enhance precision of the delivery of radiation dose to tumor tissue. Fiducial markers a...

  19. Single-snapshot 2D color measurement by plenoptic imaging system

    Science.gov (United States)

    Masuda, Kensuke; Yamanaka, Yuji; Maruyama, Go; Nagai, Sho; Hirai, Hideaki; Meng, Lingfei; Tosic, Ivana

    2014-03-01

    Plenoptic cameras enable capture of directional light ray information, thus allowing applications such as digital refocusing, depth estimation, or multiband imaging. One of the most common plenoptic camera architectures contains a microlens array at the conventional image plane and a sensor at the back focal plane of the microlens array. We leverage the multiband imaging (MBI) function of this camera and develop a single-snapshot, single-sensor high color fidelity camera. Our camera is based on a plenoptic system with XYZ filters inserted in the pupil plane of the main lens. To achieve high color measurement precision of this system, we perform an end-to-end optimization of the system model that includes light source information, object information, optical system information, plenoptic image processing and color estimation processing. Optimized system characteristics are exploited to build an XYZ plenoptic colorimetric camera prototype that achieves high color measurement precision. We describe an application of our colorimetric camera to color shading evaluation of display and show that it achieves color accuracy of ΔE<0.01.

  20. Rex shunt preoperative imaging: diagnostic capability of imaging modalities.

    Directory of Open Access Journals (Sweden)

    Sharon W Kwan

    Full Text Available The purpose of this study was to evaluate the diagnostic capability of imaging modalities used for preoperative mesenteric-left portal bypass ("Rex shunt" planning. Twenty patients with extrahepatic portal vein thrombosis underwent 57 preoperative planning abdominal imaging studies. Two readers retrospectively reviewed these studies for an ability to confidently determine left portal vein (PV patency, superior mesenteric vein (SMV patency, and intrahepatic left and right PV contiguity. In this study, computed tomographic arterial portography allowed for confident characterization of left PV patency, SMV patency and left and right PV continuity in 100% of the examinations. Single phase contrast-enhanced CT, multi-phase contrast-enhanced CT, multiphase contrast-enhanced MRI, and transarterial portography answered all key diagnostic questions in 33%, 30%, 0% and 8% of the examinations, respectively. In conclusion, of the variety of imaging modalities that have been employed for Rex shunt preoperative planning, computed tomographic arterial portography most reliably allows for assessment of left PV patency, SMV patency, and left and right PV contiguity in a single study.

  1. New Method for 2D Image Edge-detection in Layer-layer 3D Testing System

    Institute of Scientific and Technical Information of China (English)

    YANG Yu-xiao; XIONG Kai-li; ZHOU Jian; ZHAO Ming-tao; TAN Yu-shan

    2003-01-01

    A new method based on the material removal and cross-section optical scanning is investigated.The advantage of this method is that the internal and external information of the specimen can be obtained at same precision. In order to eliminate the pulse and Gaussian noise, the multi-scale dyadic wavelet methods are presented and discussed. The experimental results show that the multi-scale dyadic wavelet methods can successfully extract the features from noise image.The accuracy of 2D edge detection is 5.4 μm with the resolution of 2.7 μm.

  2. In-vivo quantification of wall motion in cerebral aneurysms from 2D cine phase contrast magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Karmonik, C. [The Methodist Hospital Research Inst., Houston (United States); Diaz, O.; Klucznik, R. [The Methodist Hospital, Houston (United States); Grossman, R. [The Methodist Hospital, Houston (United States). Neurosurgery

    2010-02-15

    Purpose: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. Materials and Methods: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative magnetic resonance angiography (QMRA) was evaluated for measuring wall motion in 7 intracranial aneurysms. In each aneurysm, 2 (in one case 3) cross sections, oriented approximately perpendicular to each other, were measured. Results: The maximum aneurysmal wall distention ranged from 0.16 mm to 1.6 mm (mean 0.67 mm), the maximum aneurysmal wall contraction was -1.91 mm to -0.34 mm (mean 0.94 mm), and the average wall displacement ranged from 0.04 mm to 0.31 mm (mean 0.15 mm). Statistically significant correlations between average wall displacement and the shape of inflow curves (p-value < 0.05) were found in 7 of 15 cross sections; statistically significant correlations between the displacement of the luminal boundary center point and the shape of inflow curves (p-value < 0.05) were found in 6 of 15 cross sections. Conclusion: 2D pcMRI in combination with QMRA is capable of visualizing and quantifying wall motion in cerebral aneurysms. However, application of this technique is currently restricted by its limited spatial resolution. (orig.)

  3. Millimeter-wave imaging diagnostics systems on the EAST tokamak (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Y. L.; Xie, J. L., E-mail: jlxie@ustc.edu.cn; Yu, C. X.; Zhao, Z. L.; Gao, B. X.; Chen, D. X.; Liu, W. D.; Liao, W.; Qu, C. M.; Luo, C. [School of Physics, University of Science and Technology of China, Anhui 230026 (China); Hu, X.; Spear, A. G.; Luhmann, N. C.; Domier, C. W.; Chen, M.; Ren, X. [University of California, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2016-11-15

    Millimeter-wave imaging diagnostics, with large poloidal span and wide radial range, have been developed on the EAST tokamak for visualization of 2D electron temperature and density fluctuations. A 384 channel (24 poloidal × 16 radial) Electron Cyclotron Emission Imaging (ECEI) system in F-band (90-140 GHz) was installed on the EAST tokamak in 2012 to provide 2D electron temperature fluctuation images with high spatial and temporal resolution. A co-located Microwave Imaging Reflectometry (MIR) will be installed for imaging of density fluctuations by December 2016. This “4th generation” MIR system has eight independent frequency illumination beams in W-band (75-110 GHz) driven by fast tuning synthesizers and active multipliers. Both of these advanced millimeter-wave imaging diagnostic systems have applied the latest techniques. A novel design philosophy “general optics structure” has been employed for the design of the ECEI and MIR receiver optics with large aperture. The extended radial and poloidal coverage of ECEI on EAST is made possible by innovations in the design of front-end optics. The front-end optical structures of the two imaging diagnostics, ECEI and MIR, have been integrated into a compact system, including the ECEI receiver and MIR transmitter and receiver. Two imaging systems share the same mid-plane port for simultaneous, co-located 2D fluctuation measurements of electron density and temperature. An intelligent remote-control is utilized in the MIR electronics systems to maintain focusing at the desired radial region even with density variations by remotely tuning the probe frequencies in about 200 μs. A similar intelligent technique has also been applied on the ECEI IF system, with remote configuration of the attenuations for each channel.

  4. Millimeter-wave imaging diagnostics systems on the EAST tokamak (invited)

    Science.gov (United States)

    Zhu, Y. L.; Xie, J. L.; Yu, C. X.; Zhao, Z. L.; Gao, B. X.; Chen, D. X.; Liu, W. D.; Liao, W.; Qu, C. M.; Luo, C.; Hu, X.; Spear, A. G.; Luhmann, N. C.; Domier, C. W.; Chen, M.; Ren, X.; Tobias, B. J.

    2016-11-01

    Millimeter-wave imaging diagnostics, with large poloidal span and wide radial range, have been developed on the EAST tokamak for visualization of 2D electron temperature and density fluctuations. A 384 channel (24 poloidal × 16 radial) Electron Cyclotron Emission Imaging (ECEI) system in F-band (90-140 GHz) was installed on the EAST tokamak in 2012 to provide 2D electron temperature fluctuation images with high spatial and temporal resolution. A co-located Microwave Imaging Reflectometry (MIR) will be installed for imaging of density fluctuations by December 2016. This "4th generation" MIR system has eight independent frequency illumination beams in W-band (75-110 GHz) driven by fast tuning synthesizers and active multipliers. Both of these advanced millimeter-wave imaging diagnostic systems have applied the latest techniques. A novel design philosophy "general optics structure" has been employed for the design of the ECEI and MIR receiver optics with large aperture. The extended radial and poloidal coverage of ECEI on EAST is made possible by innovations in the design of front-end optics. The front-end optical structures of the two imaging diagnostics, ECEI and MIR, have been integrated into a compact system, including the ECEI receiver and MIR transmitter and receiver. Two imaging systems share the same mid-plane port for simultaneous, co-located 2D fluctuation measurements of electron density and temperature. An intelligent remote-control is utilized in the MIR electronics systems to maintain focusing at the desired radial region even with density variations by remotely tuning the probe frequencies in about 200 μs. A similar intelligent technique has also been applied on the ECEI IF system, with remote configuration of the attenuations for each channel.

  5. Do medical images aid understanding and recall of medical information? An experimental study comparing the experience of viewing no image, a 2D medical image and a 3D medical image alongside a diagnosis.

    Science.gov (United States)

    Phelps, Emma Elizabeth; Wellings, Richard; Griffiths, Frances; Hutchinson, Charles; Kunar, Melina

    2017-06-01

    This study compared the experience of viewing 3D medical images, 2D medical images and no image presented alongside a diagnosis. We conducted two laboratory experiments, each with 126 healthy participants. Participants heard three diagnoses; one accompanied by 3D medical images, one accompanied by 2D medical images and one with no image. Participants completed a questionnaire after each diagnosis rating their experience. In Experiment 2, half of the participants were informed that image interpretation can be susceptible to errors. Participants preferred to view 3D images alongside a diagnosis (pmedical images may aid patient understanding, recall and trust in medical information. Medical images may be a powerful resource for patients that could be utilised by clinicians during consultations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. A 2-D Convolver Architecture For Real-Time Image Processing

    Science.gov (United States)

    Landeta, David; Malinowski, Chris W.

    1989-08-01

    This paper presents a novel architecture for two VLSI ICs, an 8-bit and 12-bit version, which execute real-time 3x3 kernel image convolutions at rates exceeding 10 ms per 512x512 pixel frame (at a 30 MHz external clock rate). The ICs are capable of performing "on-the-fly" convolutions of images without any need for external input image buffers. Both symmetric and asymmetric coefficient kernels are supported, with coefficient precision up to 12 bits. Nine on-chip multiplier-accumulators maintain double-precision accuracy for maximum precision of the results and minimum roundoff noise. In addition, an on-chip ALU can be switched into the pixel datapath to perform simultaneous pixel-point operations on the incoming data. Thus, operations such as thresholding, inversion, shifts, and double frame arithmetic can be performed on the pixels with no extra speed penalty. Flexible internal datapaths of the processors provide easy means for cascadability of several devices if larger image arrays need to be processed. Moreover, larger convolution kernels, such as 6x6, can easily be supported with no speed penalty by employing two or more convolvers. On-chip delay buffers can be programmed to any desired raster line width up to 1024 pixels. The delay buffers may also be bypassed when direct "Sum-Of-Products" operation of the multipliers is required; such as when external frame buffer address sequencing is desired. These features make the convolvers suitable for applications such as affine and bilinear interpolation, one-dimensional convolution (FIR filtration), and matrix operations. Several examples of applications illustrating stand-alone and cascade mode operation of the ICs will be discussed.

  7. Performance of 2D Compressive Sensing on Wide-Beam Through-the-Wall Imaging

    Directory of Open Access Journals (Sweden)

    Edison Cristofani

    2013-01-01

    Full Text Available Compressive sensing has become an accepted and powerful alternative to conventional data sampling schemes. Hardware simplicity, data, and measurement time reduction and simplified imagery are some of its most attractive strengths. This work aims at exploring the possibilities of using sparse vector recovery theory for actual engineering and defense- and security-oriented applications. Conventional through-the-wall imaging using a synthetic aperture configuration can also take advantage of compressive sensing by reducing data acquisition rates and omitting certain azimuth scanning positions. An ultra-wideband stepped frequency system carrying wide beam antennas performs through-the-wall imaging of a real scene, including a hollow concrete block wall and a corner reflector behind it. Random downsampling rates lower than those announced by Nyquist’s theorem both in the fast-time and azimuth domains are studied, as well as downsampling limitations for accurate imaging. Separate dictionaries are considered and modeled depending on the objects to be reconstructed: walls or point targets. Results show that an easy interpretation of through-the-wall scenes using the -norm and orthogonal matching pursuit algorithms is possible thanks to the simplification of the reconstructed scene, for which only as low as 25% of the conventional SAR data are needed.

  8. Distributed Computing Architecture for Image-Based Wavefront Sensing and 2 D FFTs

    Science.gov (United States)

    Smith, Jeffrey S.; Dean, Bruce H.; Haghani, Shadan

    2006-01-01

    Image-based wavefront sensing (WFS) provides significant advantages over interferometric-based wavefi-ont sensors such as optical design simplicity and stability. However, the image-based approach is computational intensive, and therefore, specialized high-performance computing architectures are required in applications utilizing the image-based approach. The development and testing of these high-performance computing architectures are essential to such missions as James Webb Space Telescope (JWST), Terrestial Planet Finder-Coronagraph (TPF-C and CorSpec), and Spherical Primary Optical Telescope (SPOT). The development of these specialized computing architectures require numerous two-dimensional Fourier Transforms, which necessitate an all-to-all communication when applied on a distributed computational architecture. Several solutions for distributed computing are presented with an emphasis on a 64 Node cluster of DSPs, multiple DSP FPGAs, and an application of low-diameter graph theory. Timing results and performance analysis will be presented. The solutions offered could be applied to other all-to-all communication and scientifically computationally complex problems.

  9. Diffraction Analysis of 2-D Pupil Mapping for High-Contrast Imaging

    CERN Document Server

    Vanderbei, R J

    2005-01-01

    Pupil-mapping is a technique whereby a uniformly-illuminated input pupil, such as from starlight, can be mapped into a non-uniformly illuminated exit pupil, such that the image formed from this pupil will have suppressed sidelobes, many orders of magnitude weaker than classical Airy ring intensities. Pupil mapping is therefore a candidate technique for coronagraphic imaging of extrasolar planets around nearby stars. Unlike most other high-contrast imaging techniques, pupil mapping is lossless and preserves the full angular resolution of the collecting telescope. So, it could possibly give the highest signal-to-noise ratio of any proposed single-telescope system for detecting extrasolar planets. Prior analyses based on pupil-to-pupil ray-tracing indicate that a planet fainter than 10^{-10} times its parent star, and as close as about 2 lambda/D, should be detectable. In this paper, we describe the results of careful diffraction analysis of pupil mapping systems. These results reveal a serious unresolved issue....

  10. Sequential functional analysis of left ventricle from 2D-echocardiography images.

    Science.gov (United States)

    Chacko, Rani; Singh, Megha

    2014-06-01

    The sequential changes in shape of left ventricle (LV), which are the result of cellular interactions and their levels of organizational complexity, in its long axis view during one cardiac cycle are obtained. The changes are presented in terms of shape descriptors by processing of images obtained from a normal subject and two patients with dilated left ventricular cardio-myopathy. These images are processed, frame by frame, by a semi-automatic algorithm developed by MATLAB. This is consisting of gray scale conversion, the LV contour extraction by application of median and SRAD filters, and morphological operations. By filling the identified region with pixels and number of pixels along its contour the area and perimeter are calculated, respectively. From these the changes in LV volume and shape index are calculated. Based on these the stroke volume (SV) and ejection fraction (EF) are calculated. The changes in LV area, perimeter, volume and shape index in cardiac patients are less than that of normal subject. The calculated SV and EF of normal subject are within the range as obtained by various imaging procedures.

  11. 3D–2D image registration for target localization in spine surgery: investigation of similarity metrics providing robustness to content mismatch

    OpenAIRE

    Silva, T.; Uneri, A.; Ketcha, M. D.; Reaungamornrat, S.; Kleinszig, G.; Vogt, S; Aygun, N; Lo, S-F; Wolinsky, J-P; Siewerdsen, J. H.

    2016-01-01

    In image-guided spine surgery, robust three-dimensional to two-dimensional (3D–2D) registration of preoperative computed tomography (CT) and intraoperative radiographs can be challenged by the image content mismatch associated with the presence of surgical instrumentation and implants as well as soft-tissue resection or deformation. This work investigates image similarity metrics in 3D–2D registration offering improved robustness against mismatch, thereby improving performance and reducing or...

  12. 2D and 3D GPR imaging of structural ceilings in historic and existing constructions

    Science.gov (United States)

    Colla, Camilla

    2014-05-01

    GPR applications in civil engineering are to date quite diversified. With respect to civil constructions and monumental buildings, detection of voids, cavities, layering in structural elements, variation of geometry, of moisture content, of materials, areas of decay, defects, cracks have been reported in timber, concrete and masonry elements. Nonetheless, many more fields of investigation remain unexplored. This contribution gives an account of a variety of examples of structural ceilings investigation by GPR radar in reflection mode, either as 2D or 3D data acquisition and visualisation. Ceilings have a pre-eminent role in buildings as they contribute to a good structural behaviour of the construction. Primarily, the following functions can be listed for ceilings: a) they carry vertical dead and live loads on floors and distribute such loads to the vertical walls; b) they oppose to external horizontal forces such as wind loads and earthquakes helping to transfer such forces from the loaded element to the other walls; c) they contribute to create the box skeleton and behaviour of a building, connecting the different load bearing walls and reducing the slenderness and flexural instability of such walls. Therefore, knowing how ceilings are made in specific buildings is of paramount importance for architects and structural engineers. According to the type of building and age of construction, ceilings may present very different solutions and materials. Moreover, in existing constructions, ceilings may have been substituted, modified or strengthened due to material decay or to change of use of the building. These alterations may often go unrecorded in technical documentation or technical drawings may be unavailable. In many cases, the position, orientation and number of the load carrying elements in ceilings may be hidden or not be in sight, due for example to the presence of false ceilings or to technical plants. GPR radar can constitute a very useful tool for

  13. Correlation and convolution filtering and image processing for pitch evaluation of 2D micro- and nano-scale gratings and lattices

    OpenAIRE

    Chen, Xiaomei; Koenders, Ludger; Parkinson, Simon

    2017-01-01

    We have mathematically explicated and experimentally demonstrated how a correlation and convolution filter can dramatically suppress the noise that coexists with the scanned topographic signals of 2D gratings and lattices with 2-dimensional (2D) perspectives. To realize pitch evaluation, the true peaks’ coordinates have been precisely acquired after detecting the local maxima from the filtered signal, followed by image processing. The combination of 2D filtering, local-maxima dete...

  14. Automatic Evaluation of Scan Adequacy and Dysplasia Metrics in 2-D Ultrasound Images of the Neonatal Hip.

    Science.gov (United States)

    Quader, Niamul; Hodgson, Antony J; Mulpuri, Kishore; Schaeffer, Emily; Abugharbieh, Rafeef

    2017-06-01

    Ultrasound (US) imaging of an infant's hip joint is widely used for early detection of developmental dysplasia of the hip. In current US-based diagnosis of developmental dysplasia of the hip, trained clinicians acquire US images and, if they judge them to be adequate (i.e., to contain relevant hip joint structures), analyze them manually to extract clinically useful dysplasia metrics. However, both the scan adequacy classification and dysplasia metrics extraction steps exhibit significant variability within and between both clinicians and institutions, which can result in significant over- and undertreatment rates. To reduce the subjectivity resulting from this variability, we propose a computational image analysis technique that automatically identifies adequate images and subsequently extracts dysplasia metrics from these 2-D US images. Our automatic method uses local phase symmetry-based image measures to robustly identify intensity-invariant geometric features of bone/cartilage boundaries from the US images. Using the extracted geometric features, we trained a random forest classifier to classify images as adequate or inadequate, and in the adequate images we used a subset of the geometric features to calculate key dysplasia metrics. We validated our method on a data set of 693 US scans collected from 35 infants. Our approach produces excellent agreement with clinician adequacy classifications (area under the receiver operating characteristic curve = 0.985) and in reducing variability in the measured developmental dysplasia of the hip metrics (p dysplasia metrics appear to be slightly biased toward higher Graf categories than the manually estimated metrics, which could potentially reduce missed early diagnoses. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  15. Application of Compressed Sensing to 2-D Ultrasonic Propagation Imaging System data

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenas, David D. [Los Alamos National Laboratory; Farrar, Charles R. [Los Alamos National Laboratory; Chong, See Yenn [Engineering Institute-Korea; Lee, J.R. [Engineering Institute-Korea; Park, Gyu Hae [Los Alamos National Laboratory; Flynn, Eric B. [Los Alamos National Laboratory

    2012-06-29

    The Ultrasonic Propagation Imaging (UPI) System is a unique, non-contact, laser-based ultrasonic excitation and measurement system developed for structural health monitoring applications. The UPI system imparts laser-induced ultrasonic excitations at user-defined locations on a structure of interest. The response of these excitations is then measured by piezoelectric transducers. By using appropriate data reconstruction techniques, a time-evolving image of the response can be generated. A representative measurement of a plate might contain 800x800 spatial data measurement locations and each measurement location might be sampled at 500 instances in time. The result is a total of 640,000 measurement locations and 320,000,000 unique measurements. This is clearly a very large set of data to collect, store in memory and process. The value of these ultrasonic response images for structural health monitoring applications makes tackling these challenges worthwhile. Recently compressed sensing has presented itself as a candidate solution for directly collecting relevant information from sparse, high-dimensional measurements. The main idea behind compressed sensing is that by directly collecting a relatively small number of coefficients it is possible to reconstruct the original measurement. The coefficients are obtained from linear combinations of (what would have been the original direct) measurements. Often compressed sensing research is simulated by generating compressed coefficients from conventionally collected measurements. The simulation approach is necessary because the direct collection of compressed coefficients often requires compressed sensing analog front-ends that are currently not commercially available. The ability of the UPI system to make measurements at user-defined locations presents a unique capability on which compressed measurement techniques may be directly applied. The application of compressed sensing techniques on this data holds the potential to

  16. 2D and 3D Terahertz Imaging and X-Rays CT for Sigillography Study

    Science.gov (United States)

    Fabre, M.; Durand, R.; Bassel, L.; Recur, B.; Balacey, H.; Bou Sleiman, J.; Perraud, J.-B.; Mounaix, P.

    2017-04-01

    Seals are part of our cultural heritage but the study of these objects is limited because of their fragility. Terahertz and X-Ray imaging are used to analyze a collection of wax seals from the fourteenth to eighteenth centuries. In this work, both techniques are compared in order to discuss their advantages and limits and their complementarity for conservation state study of the samples. Thanks to 3D analysis and reconstructions, defects and fractures are detected with an estimation of their depth position. The path from the parchment tongue inside the seals is also detected.

  17. Imaging diagnostics of the foot; Bildgebende Diagnostik des Fusses

    Energy Technology Data Exchange (ETDEWEB)

    Szeimies, Ulrike; Staebler, Axel [Radiologie in Muenchen-Harlaching, Muenchen (Germany); Walther, Markus (eds.) [Schoen-Klinik Muenchen-Harlaching, Muenchen (Germany). Zentrum fuer Fuss- und Sprunggelenkchirurgie

    2012-11-01

    The book on imaging diagnostics of the foot contains the following chapters: (1) Imaging techniques. (2) Clinical diagnostics. (3) Ankle joint and hind foot. (4) Metatarsus. (5) Forefoot. (6) Pathology of plantar soft tissue. (7) Nervous system diseases. (8) Diseases without specific anatomic localization. (9) System diseases including the foot. (10) Tumor like lesions. (11) Normative variants.

  18. 基于CUDA的2D-3D医学图像快速配准%Rapid 2D-3D Medical Image Registration Based on CUDA

    Institute of Scientific and Technical Information of China (English)

    李玲芝; 邹北骥

    2014-01-01

    医学三维扫描体数据和二维图像配准在临床诊断、手术规划等领域应用广泛,特别是在手术导航时,三维扫描体数据和二维图像的结合既需要保证配准的精度,又要达到手术中即时应用的要求.本文提出一种混合几何和图像密度特征构成的相似度度量函数,对术前CT和术中X线图像进行快速的2D-3D配准,其实现方便、计算量小,同时计算精度可以满足正常的需要.另外,整个计算过程非常适合高度并行的数值计算,通过采用基于CUDA的硬件加速算法,能够达到手术中即时应用的要求.

  19. A Stochastic Hill Climbing Approach for Simultaneous 2D Alignment and Clustering of Cryogenic Electron Microscopy Images.

    Science.gov (United States)

    Reboul, Cyril F; Bonnet, Frederic; Elmlund, Dominika; Elmlund, Hans

    2016-06-07

    A critical step in the analysis of novel cryogenic electron microscopy (cryo-EM) single-particle datasets is the identification of homogeneous subsets of images. Methods for solving this problem are important for data quality assessment, ab initio 3D reconstruction, and analysis of population diversity due to the heterogeneous nature of macromolecules. Here we formulate a stochastic algorithm for identification of homogeneous subsets of images. The purpose of the method is to generate improved 2D class averages that can be used to produce a reliable 3D starting model in a rapid and unbiased fashion. We show that our method overcomes inherent limitations of widely used clustering approaches and proceed to test the approach on six publicly available experimental cryo-EM datasets. We conclude that, in each instance, ab initio 3D reconstructions of quality suitable for initialization of high-resolution refinement are produced from the cluster centers.

  20. Understanding 2D atomic resolution imaging of the calcite surface in water by frequency modulation atomic force microscopy

    Science.gov (United States)

    Tracey, John; Miyazawa, Keisuke; Spijker, Peter; Miyata, Kazuki; Reischl, Bernhard; Federici Canova, Filippo; Rohl, Andrew L.; Fukuma, Takeshi; Foster, Adam S.

    2016-10-01

    Frequency modulation atomic force microscopy (FM-AFM) experiments were performed on the calcite (10\\bar{1}4) surface in pure water, and a detailed analysis was made of the 2D images at a variety of frequency setpoints. We observed eight different contrast patterns that reproducibly appeared in different experiments and with different measurement parameters. We then performed systematic free energy calculations of the same system using atomistic molecular dynamics to obtain an effective force field for the tip-surface interaction. By using this force field in a virtual AFM simulation we found that each experimental contrast could be reproduced in our simulations by changing the setpoint, regardless of the experimental parameters. This approach offers a generic method for understanding the wide variety of contrast patterns seen on the calcite surface in water, and is generally applicable to AFM imaging in liquids.

  1. A Gaseous Compton Camera using a 2D-sensitive gaseous photomultiplier for Nuclear Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, C.D.R., E-mail: cdazevedo@ua.pt; Pereira, F.A.; Lopes, T.; Correia, P.M.M.; Silva, A.L.M.; Carramate, L.F.N.D.; Covita, D.S.; Veloso, J.F.C.A.

    2013-12-21

    A new Compton Camera (CC) concept based on a High Pressure Scintillation Chamber coupled to a position-sensitive Gaseous PhotoMultiplier for Nuclear Medical Imaging applications is proposed. The main goal of this work is to describe the development of a ϕ25×12cm{sup 3} cylindrical prototype, which will be suitable for scintimammography and for small-animal imaging applications. The possibility to scale it to an useful human size device is also in study. The idea is to develop a device capable to compete with the standard Anger Camera. Despite the large success of the Anger Camera, it still presents some limitations, such as: low position resolution and fair energy resolutions for 140 keV. The CC arises a different solution as it provides information about the incoming photon direction, avoiding the use of a collimator, which is responsible for a huge reduction (10{sup −4}) of the sensitivity. The main problem of the CC's is related with the Doppler Broadening which is responsible for the loss of angular resolution. In this work, calculations for the Doppler Broadening in Xe, Ar, Ne and their mixtures are presented. Simulations of the detector performance together with discussion about the gas choice are also included.

  2. High-accuracy 2D digital image correlation measurements using low-cost imaging lenses: implementation of a generalized compensation method

    Science.gov (United States)

    Pan, Bing; Yu, Liping; Wu, Dafang

    2014-02-01

    The ideal pinhole imaging model commonly assumed for an ordinary two-dimensional digital image correlation (2D-DIC) system is neither perfect nor stable because of the existence of small out-of-plane motion of the test sample surface that occurred after loading, small out-of-plane motion of the sensor target due to temperature variation of a camera and unavoidable geometric distortion of an imaging lens. In certain cases, these disadvantages can lead to significant errors in the measured displacements and strains. Although a high-quality bilateral telecentric lens has been strongly recommended to be used in the 2D-DIC system as an essential optical component to achieve high-accuracy measurement, it is not generally applicable due to its fixed field of view, limited depth of focus and high cost. To minimize the errors associated with the imperfectness and instability of a common 2D-DIC system using a low-cost imaging lens, a generalized compensation method using a non-deformable reference sample is proposed in this work. With the proposed method, the displacement of the reference sample rigidly attached behind the test sample is first measured using 2D-DIC, and then it is fitted using a parametric model. The fitted parametric model is then used to correct the displacements of the deformed sample to remove the influences of these unfavorable factors. The validity of the proposed compensation method is first verified using out-of-plane translation, out-of-plane rotation, in-plane translation tests and their combinations. Uniaxial tensile tests of an aluminum specimen were also performed to quantitatively examine the strain accuracy of the proposed compensation method. Experiments show that the proposed compensation method is an easy-to-implement yet effective technique for achieving high-accuracy deformation measurement using an ordinary 2D-DIC system.

  3. Quantitative Comparison of 2D and 3D MRI Techniques for the Evaluation of Chondromalacia Patellae in 3.0T MR Imaging of the Knee

    Directory of Open Access Journals (Sweden)

    Ali Özgen

    2016-09-01

    Full Text Available INTRODUCTION: Chondromalacia patellae is a very common disorder of patellar cartilage. Magnetic resonance imaging (MRI is a powerful non-invasive tool to investigate patellar cartilage lesions. Although many MRI sequences have been used in MR imaging of the patellar cartilage and the optimal pulse sequence is controversial, fat-saturated proton density images have been considered very valuable to evaluate patellar cartilage. The purpose of this study is to quantitatively compare the diagnostic performance of various widely used 2D and 3D MRI techniques for the evaluation of chondromalacia patellae in 3.0T MR imaging of the knee using T2 mapping images as the reference standard. METHODS: Sevety-five knee MRI exams of 69 adult consecutive were included in the study. Fat-saturated T2-weighted (FST2, fat-saturated proton density (FSPD, water-only T2-weighted DIXON (T2mD, T2-weighted 3 dimensional steady state (3DT2FFE, merged multi-echo steady state (3DmFFE, and water selective T1-weighted fat-supressed (WATSc images were acquired. Quantitative comparison of grade 1 and grade 5 lesions were made using contrast-to-noise (CNR ratios. Grade 2-4 lesions were scored qualitatively and scorings of the lesions were compared statistically. Analysis of variance and Tukey’s tests were used to compare CNR data. Two sample z-test was used to compare the ratio of MR exams positive for grade 1 lesions noted on T2-mapping and other conventional sequences. Paired samples t-test was used to compare two different pulse sequences. RESULTS: In detecting grade 1 lesions, FSPD, FST2 and T2mD images were superior in comparison to other sequences. FSPD and FST2 images were statistically superior in detecting grade 2-4 lesions. Although all grade 5 lesions were noted in every single sequence, FST2 images have the highest mean CNR followed by 3DT2FFE images. DISCUSSION AND CONCLUSION: FST2 sequence is equal or superior in detecting every grade of patellar chondromalacia in

  4. Real-time texture analysis for identifying optimum microbubble concentration in 2-D ultrasonic particle image velocimetry.

    Science.gov (United States)

    Niu, Lili; Qian, Ming; Yan, Liang; Yu, Wentao; Jiang, Bo; Jin, Qiaofeng; Wang, Yanping; Shandas, Robin; Liu, Xin; Zheng, Hairong

    2011-08-01

    Many recent studies on ultrasonic particle image velocimetry (Echo PIV) showed that the accuracy of two-dimensional (2-D) flow velocity measured depends largely on the concentration of ultrasound contrast agents (UCAs) during imaging. This article presents a texture-based method for identifying the optimum microbubble concentration for Echo PIV measurements in real-time. The texture features, standard deviation of gray level, and contrast, energy and homogeneity of gray level co-occurrence matrix were extracted from ultrasound contrast images of rotational and pulsatile flow (10 MHz) in vitro and in vivo mouse common carotid arterial flow (40 MHz) with UCAs at various concentrations. The results showed that, at concentration of 0.8∼2 × 10³ bubbles/mL in vitro and 1∼5 × 10⁵ bubbles/mL in vivo, image texture features had a peak value or trough value, and velocity vectors with high accuracy can be obtained. Otherwise, poor quality velocity vectors were obtained. When the texture features were used as a feature set, the accuracy of K-nearest neighbor classifier can reach 86.4% in vitro and 87.5% in vivo, respectively. The texture-based method is shown to be able to quickly identify the optimum microbubble concentration and improve the accuracy for Echo PIV imaging.

  5. A new computational approach to cracks quantification from 2D image analysis: Application to micro-cracks description in rocks

    Science.gov (United States)

    Arena, Alessio; Delle Piane, Claudio; Sarout, Joel

    2014-05-01

    In this paper we propose a crack quantification method based on 2D image analysis. This technique is applied to a gray level Scanning Electron Microscope (SEM) images, segmented and converted in Black and White (B/W) images using the Trainable Segmentation plugin of Fiji. Resulting images are processed using a novel Matlab script composed of three different algorithms: the separation algorithm, the filtering and quantification algorithm and the orientation one. Initially the input image is enhanced via 5 morphological processes. The resulting lattice is “cut” into single cracks using 1 pixel-wide bisector lines originated from every node. Cracks are labeled using the connected-component method, then the script computes geometrical parameters, such as width, length, area, aspect ratio and orientation. A filtering is performed using a user-defined value of aspect ratio, followed by a statistical analysis of remaining cracks. In the last part of this paper we discuss about the efficiency of this script, introducing an example of analysis of two datasets with different dimension and resolution; these analyses are performed using a notebook and a high-end professional desktop solution, in order to simulate different working environments.

  6. High Speed and Area Efficient 2D DWT Processor Based Image Compression

    Directory of Open Access Journals (Sweden)

    Sugreev Kaur

    2011-02-01

    Full Text Available This paper presents a high speed and area efficient DWT processor based design for Image Compressionapplications. In this proposed design, pipelined partially serial architecture has been used to enhance thespeed along with optimal utilization and resources available on target FPGA. The proposed model hasbeen designed and simulated using Simulink and System Generator blocks, synthesized with XilinxSynthesis tool (XST and implemented on Spartan 2 and 3 based XC2S100-5tq144 and XC3S500E-4fg320target device. The results show that proposed design can operate at maximum frequency 231 MHz in caseof Spartan 3 by consuming power of 117mW at 28 degree/c junction temperature. The result comparisonhas shown an improvement of 15% in speed.

  7. 3D/2D Registration of Mapping Catheter Images for Arrhythmia Interventional Assistance

    Directory of Open Access Journals (Sweden)

    Pascal Fallavollita

    2009-09-01

    Full Text Available Radiofrequency (RF catheter ablation has transformed treatment for tachyarrhythmias and has become first-line therapy for some tachycardias. The precise localization of the arrhythmogenic site and the positioning of the RF catheter over that site are problematic: they can impair the efficiency of the procedure and are time consuming (several hours. Electroanatomic mapping technologies are available that enable the display of the cardiac chambers and the relative position of ablation lesions. However, these are expensive and use custom-made catheters. The proposed methodology makes use of standard catheters and inexpensive technology in order to create a 3D volume of the heart chamber affected by the arrhythmia. Further, we propose a novel method that uses a priori 3D information of the mapping catheter in order to estimate the 3D locations of multiple electrodes across single view C-arm images. The monoplane algorithm is tested for feasibility on computer simulations and initial canine data.

  8. Impact of lens distortions on strain measurements obtained with 2D digital image correlation

    Science.gov (United States)

    Lava, P.; Van Paepegem, W.; Coppieters, S.; De Baere, I.; Wang, Y.; Debruyne, D.

    2013-05-01

    The determination of strain fields based on displacements obtained via digital image correlation (DIC) at the micro-strain level (≤1000 μm/m) is still a cumbersome task. In particular when high-strain gradients are involved, e.g. in composite materials with multidirectional fibre reinforcement, uncertainties in the experimental setup and errors in the derivation of the displacement fields can substantially hamper the strain identification process. In this contribution, the aim is to investigate the impact of lens distortions on strain measurements. To this purpose, we first perform pure rigid body motion experiments, revealing the importance of precise correction of lens distortions. Next, a uni-axial tensile test on a textile composite with spatially varying high strain gradients is performed, resulting in very accurately determined strains along the fibers of the material.

  9. 3D/2D Registration of Mapping Catheter Images for Arrhythmia Interventional Assistance

    CERN Document Server

    Fallavollita, Pascal

    2009-01-01

    Radiofrequency (RF) catheter ablation has transformed treatment for tachyarrhythmias and has become first-line therapy for some tachycardias. The precise localization of the arrhythmogenic site and the positioning of the RF catheter over that site are problematic: they can impair the efficiency of the procedure and are time consuming (several hours). Electroanatomic mapping technologies are available that enable the display of the cardiac chambers and the relative position of ablation lesions. However, these are expensive and use custom-made catheters. The proposed methodology makes use of standard catheters and inexpensive technology in order to create a 3D volume of the heart chamber affected by the arrhythmia. Further, we propose a novel method that uses a priori 3D information of the mapping catheter in order to estimate the 3D locations of multiple electrodes across single view C-arm images. The monoplane algorithm is tested for feasibility on computer simulations and initial canine data.

  10. Fast 2-D ultrasound strain imaging: the benefits of using a GPU.

    Science.gov (United States)

    Idzenga, Tim; Gaburov, Evghenii; Vermin, Willem; Menssen, Jan; de Korte, Chris

    2014-01-01

    Deformation of tissue can be accurately estimated from radio-frequency ultrasound data using a 2-dimensional normalized cross correlation (NCC)-based algorithm. This procedure, however, is very computationally time-consuming. A major time reduction can be achieved by parallelizing the numerous computations of NCC. In this paper, two approaches for parallelization have been investigated: the OpenMP interface on a multi-CPU system and Compute Unified Device Architecture (CUDA) on a graphics processing unit (GPU). The performance of the OpenMP and GPU approaches were compared with a conventional Matlab implementation of NCC. The OpenMP approach with 8 threads achieved a maximum speed-up factor of 132 on the computing of NCC, whereas the GPU approach on an Nvidia Tesla K20 achieved a maximum speed-up factor of 376. Neither parallelization approach resulted in a significant loss in image quality of the elastograms. Parallelization of the NCC computations using the GPU, therefore, significantly reduces the computation time and increases the frame rate for motion estimation.

  11. On non-invasive 2D and 3D Chromatic White Light image sensors for age determination of latent fingerprints.

    Science.gov (United States)

    Merkel, Ronny; Gruhn, Stefan; Dittmann, Jana; Vielhauer, Claus; Bräutigam, Anja

    2012-10-10

    The feasibility of 2D-intensity and 3D-topography images from a non-invasive Chromatic White Light (CWL) sensor for the age determination of latent fingerprints is investigated. The proposed method might provide the means to solve the so far unresolved issue of determining a fingerprints age in forensics. Conducting numerous experiments for an indoor crime scene using selected surfaces, different influences on the aging of fingerprints are investigated and the resulting aging variability is determined in terms of inter-person, intra-person, inter-finger and intra-finger variation. Main influence factors are shown to be the sweat composition, temperature, humidity, wind, UV-radiation, surface type, contamination of the finger with water-containing substances, resolution and measured area size, whereas contact time, contact pressure and smearing of the print seem to be of minor importance. Such influences lead to a certain experimental variability in inter-person and intra-person variation, which is higher than the inter-finger and intra-finger variation. Comparing the aging behavior of 17 different features using 1490 time series with a total of 41,520 fingerprint images, the great potential of the CWL technique in combination with the binary pixel feature from prior work is shown. Performing three different experiments for the classification of fingerprints into the two time classes [0, 5 h] and [5, 24 h], a maximum classification performance of 79.29% (kappa=0.46) is achieved for a general case, which is further improved for special cases. The statistical significance of the two best-performing features (both binary pixel versions based on 2D-intensity images) is manually shown and a feature fusion is performed, highlighting the strong dependency of the features on each other. It is concluded that such method might be combined with additional capturing devices, such as microscopes or spectroscopes, to a very promising age estimation scheme.

  12. A Statistical Method for Analysis of Technical Data of a Badminton Match Based on 2-D Seriate Images

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The use of computer vision technology to collect and analyze statistics during badminton matches or training sessions can be expected to provide valuable information to help coaches to determine which tactics should be used by a player in a given game or to improve the player's tactical training. A method based on 2-D seriate images by which statistical data of a badminton match can be obtained is presented. Image capture and analysis were performed synchronously using a multithreading technique. The regions of movement in the images were detected using a temporal difference method, and the trajectories of the movement regions were analyzed using seriate images. The shuttlecock trajectory was extracted from all detected trajectories using various characteristic parameters. The stroke type was determined by comparing the shuttlecock trajectory data with a set of stroke definition data. The algorithm was tested at a training center, and the results were compared with baseline data obtained by expert visual inspection using four video samples, which included approximately 10 000 frames. The shuttlecock trajectory and stroke type were detected correctly in almost 100% of the analyzed video sequences. The average speed of the automated analysis was approximately 40 frames/s, indicating that the method can be used for real-time analysis during a badminton match. The system is convenient for use by a sports coach.

  13. Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid

    Energy Technology Data Exchange (ETDEWEB)

    Abdoli, Mehrsima; Jong, Johan R. de; Pruim, Jan; Dierckx, Rudi A.J.O. [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Zaidi, Habib [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland)

    2011-12-15

    Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over- or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron emission tomography (PET) images. Since this degrades the diagnostic quality of the images, metal artefact reduction (MAR) prior to attenuation correction is required. The proposed MAR method, referred to as virtual sinogram-based technique, replaces the projection bins of the sinogram that are influenced by metallic implants by a 2-D Clough-Tocher cubic interpolation scheme performed in an irregular grid, called Delaunay triangulated grid. To assess the performance of the proposed method, a physical phantom and 30 clinical PET/CT studies including hip prostheses were used. The results were compared to the method implemented on the Siemens Biograph mCT PET/CT scanner. Both phantom and clinical studies revealed that the proposed method performs equally well as the Siemens MAR method in the regions corresponding to bright streaking artefacts and the artefact-free regions. However, in regions corresponding to dark streaking artefacts, the Siemens method does not seem to appropriately correct the tracer uptake while the proposed method consistently increased the uptake in the underestimated regions, thus bringing it to the expected level. This observation is corroborated by the experimental phantom study which demonstrates that the proposed method approaches the true activity concentration more closely. The proposed MAR method allows more accurate CT-based attenuation correction of PET images and prevents misinterpretation of tracer uptake, which might be biased owing to the propagation of bright and dark streaking artefacts from CT images to the PET data following the attenuation correction procedure. (orig.)

  14. Synthetic aperture microwave imaging with active probing for fusion plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Shevchenko, Vladimir F.; Freethy, Simon J.; Huang, Billy K. [EURATOM/CCFE Fusion Association, Culham, Abingdon, Oxon, 0X14 3DB (United Kingdom); Vann, Roddy G. L. [York Plasma Institute, Dept. of Physics, University of York, York YO10 5DD (United Kingdom)

    2014-08-21

    A Synthetic Aperture Microwave Imaging (SAMI) system has been designed and built to obtain 2-D images at several frequencies from fusion plasmas. SAMI uses a phased array of linearly polarised antennas. The array configuration has been optimised to achieve maximum synthetic aperture beam efficiency. The signals received by antennas are down-converted to the intermediate frequency range and then recorded in a full vector form. Full vector signals allow beam focusing and image reconstruction in both real time and a post-processing mode. SAMI can scan over 16 pre-programmed frequencies in the range of 10-35GHz with a switching time of 300ns. The system operates in 2 different modes simultaneously: both a 'passive' imaging of plasma emission and also an 'active' imaging of the back-scattered signal of the radiation launched by one of the antennas from the same array. This second mode is similar to so-called Doppler backscattering (DBS) reflectometry with 2-D resolution of the propagation velocity of turbulent structures. Both modes of operation show good performance in fusion plasma experiments on Mega Amp Spherical Tokamak (MAST). We have obtained the first ever 2-D images of BXO mode conversion windows. With active probing, first ever turbulence velocity maps have been obtained. We present an overview of the diagnostic and discuss recent results. In contrast to quasi-optical microwave imaging systems SAMI requires neither big aperture viewing ports nor large 2-D detector arrays to achieve the desired imaging resolution. The number of effective 'pixels' of the synthesized image is proportional to the number of receiving antennas squared. Thus only a small number of optimised antennas is sufficient for the majority of applications. Possible implementation of SAMI on ITERand DEMO is discussed.

  15. Synthetic aperture microwave imaging with active probing for fusion plasma diagnostics

    Science.gov (United States)

    Shevchenko, Vladimir F.; Freethy, Simon J.; Huang, Billy K.; Vann, Roddy G. L.

    2014-08-01

    A Synthetic Aperture Microwave Imaging (SAMI) system has been designed and built to obtain 2-D images at several frequencies from fusion plasmas. SAMI uses a phased array of linearly polarised antennas. The array configuration has been optimised to achieve maximum synthetic aperture beam efficiency. The signals received by antennas are down-converted to the intermediate frequency range and then recorded in a full vector form. Full vector signals allow beam focusing and image reconstruction in both real time and a post-processing mode. SAMI can scan over 16 pre-programmed frequencies in the range of 10-35GHz with a switching time of 300ns. The system operates in 2 different modes simultaneously: both a 'passive' imaging of plasma emission and also an 'active' imaging of the back-scattered signal of the radiation launched by one of the antennas from the same array. This second mode is similar to so-called Doppler backscattering (DBS) reflectometry with 2-D resolution of the propagation velocity of turbulent structures. Both modes of operation show good performance in fusion plasma experiments on Mega Amp Spherical Tokamak (MAST). We have obtained the first ever 2-D images of BXO mode conversion windows. With active probing, first ever turbulence velocity maps have been obtained. We present an overview of the diagnostic and discuss recent results. In contrast to quasi-optical microwave imaging systems SAMI requires neither big aperture viewing ports nor large 2-D detector arrays to achieve the desired imaging resolution. The number of effective 'pixels' of the synthesized image is proportional to the number of receiving antennas squared. Thus only a small number of optimised antennas is sufficient for the majority of applications. Possible implementation of SAMI on ITERand DEMO is discussed.

  16. A 256 x 256 2-D array transducer with row-column addressing for 3-D rectilinear imaging.

    Science.gov (United States)

    Seo, Chi Hyung; Yen, Jesse T

    2009-04-01

    We present simulation and experimental results from a 5-MHz, 256 x 256 2-D (65,536 elements, 38.4 x 38.4 mm) 2-D array transducer with row-column addressing. The main benefits of this design are a reduced number of interconnects, a modified transmit/receive switching scheme with a simple diode circuit, and an ability to perform volumetric imaging of targets near the transducer with transmit beamforming in azimuth and receive beamforming in elevation. The final dimensions of the transducer were 38.4 mm x 38.4 mm x 300 microm. After a row-column transducer was prototyped, the series resonance impedance was 104 Omega at 5.4 MHz. The measured -6 dB fractional bandwidth was 53% with a center frequency of 5.3 MHz. The SNR at the transmit focus was measured to be 30 dB. At 5 MHz, the average nearest neighbor crosstalk was -25 dB. In this paper, we present 3-D images of both 5 pairs of nylon wires embedded in a clear gelatin phantom and an 8 mm diameter cylindrical anechoic cyst phantom acquired from a 256 x 256 2-D array transducer made from a 1-3 composite. We display the azimuth and elevation B-scans as well as the C-scan for each image. The cross-section of the wires is visible in the azimuth B-scan, and the long axes can be seen in the elevation B-scan and C-scans. The pair of wires with 1-mm axial separation is discernible in the elevational B-scan. When a single wire from the wire target phantom was used, the measured lateral beamwidth was 0.68 mm and 0.70 mm at 30 mm depth in transmit beamforming and receive beamforming, respectively, compared with the simulated beamwidth of 0.55 mm. The cross-section of the cyst is visible in the azimuth B-scan whereas the long axes can be seen as a rectangle in the elevation B-scan and C-scans.

  17. The cone penetration test and 2D imaging resistivity as tools to simulate the distribution of hydrocarbons in soil

    Science.gov (United States)

    Pérez-Corona, M.; García, J. A.; Taller, G.; Polgár, D.; Bustos, E.; Plank, Z.

    2016-02-01

    The purpose of geophysical electrical surveys is to determine the subsurface resistivity distribution by making measurements on the ground surface. From these measurements, the true resistivity of the subsurface can be estimated. The ground resistivity is related to various geological parameters, such as the mineral and fluid content, porosity and degree of water saturation in the rock. Electrical resistivity surveys have been used for many decades in hydrogeological, mining and geotechnical investigations. More recently, they have been used for environmental surveys. To obtain a more accurate subsurface model than is possible with a simple 1-D model, a more complex model must be used. In a 2-D model, the resistivity values are allowed to vary in one horizontal direction (usually referred to as the x direction) but are assumed to be constant in the other horizontal (the y) direction. A more realistic model would be a fully 3-D model where the resistivity values are allowed to change in all three directions. In this research, a simulation of the cone penetration test and 2D imaging resistivity are used as tools to simulate the distribution of hydrocarbons in soil.

  18. Constraining Polarized Foregrounds for EoR Experiments I: 2D Power Spectra from the PAPER-32 Imaging Array

    Science.gov (United States)

    Kohn, S. A.; Aguirre, J. E.; Nunhokee, C. D.; Bernardi, G.; Pober, J. C.; Ali, Z. S.; Bradley, R. F.; Carilli, C. L.; DeBoer, D. R.; Gugliucci, N. E.; Jacobs, D. C.; Klima, P.; MacMahon, D. H. E.; Manley, J. R.; Moore, D. F.; Parsons, A. R.; Stefan, I. I.; Walbrugh, W. P.

    2016-06-01

    Current generation low-frequency interferometers constructed with the objective of detecting the high-redshift 21 cm background aim to generate power spectra of the brightness temperature contrast of neutral hydrogen in primordial intergalactic medium. Two-dimensional (2D) power spectra (power in Fourier modes parallel and perpendicular to the line of sight) that formed from interferometric visibilities have been shown to delineate a boundary between spectrally smooth foregrounds (known as the wedge) and spectrally structured 21 cm background emission (the EoR window). However, polarized foregrounds are known to possess spectral structure due to Faraday rotation, which can leak into the EoR window. In this work we create and analyze 2D power spectra from the PAPER-32 imaging array in Stokes I, Q, U, and V. These allow us to observe and diagnose systematic effects in our calibration at high signal-to-noise within the Fourier space most relevant to EoR experiments. We observe well-defined windows in the Stokes visibilities, with Stokes Q, U, and V power spectra sharing a similar wedge shape to that seen in Stokes I. With modest polarization calibration, we see no evidence that polarization calibration errors move power outside the wedge in any Stokes visibility to the noise levels attained. Deeper integrations will be required to confirm that this behavior persists to the depth required for EoR detection.

  19. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

    2015-06-15

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  20. Robust 3D-2D image registration: application to spine interventions and vertebral labeling in the presence of anatomical deformation

    Science.gov (United States)

    Otake, Yoshito; Wang, Adam S.; Webster Stayman, J.; Uneri, Ali; Kleinszig, Gerhard; Vogt, Sebastian; Khanna, A. Jay; Gokaslan, Ziya L.; Siewerdsen, Jeffrey H.

    2013-12-01

    We present a framework for robustly estimating registration between a 3D volume image and a 2D projection image and evaluate its precision and robustness in spine interventions for vertebral localization in the presence of anatomical deformation. The framework employs a normalized gradient information similarity metric and multi-start covariance matrix adaptation evolution strategy optimization with local-restarts, which provided improved robustness against deformation and content mismatch. The parallelized implementation allowed orders-of-magnitude acceleration in computation time and improved the robustness of registration via multi-start global optimization. Experiments involved a cadaver specimen and two CT datasets (supine and prone) and 36 C-arm fluoroscopy images acquired with the specimen in four positions (supine, prone, supine with lordosis, prone with kyphosis), three regions (thoracic, abdominal, and lumbar), and three levels of geometric magnification (1.7, 2.0, 2.4). Registration accuracy was evaluated in terms of projection distance error (PDE) between the estimated and true target points in the projection image, including 14 400 random trials (200 trials on the 72 registration scenarios) with initialization error up to ±200 mm and ±10°. The resulting median PDE was better than 0.1 mm in all cases, depending somewhat on the resolution of input CT and fluoroscopy images. The cadaver experiments illustrated the tradeoff between robustness and computation time, yielding a success rate of 99.993% in vertebral labeling (with ‘success’ defined as PDE registration could be solved with 99.993% success in 6.3 s. The ability to register CT to fluoroscopy in a manner robust to patient deformation could be valuable in applications such as radiation therapy, interventional radiology, and an assistant to target localization (e.g., vertebral labeling) in image-guided spine surgery.

  1. An important criterion for reliable multi-monochromatic x-ray imager diagnostics and its impact on the reconstructed images

    Institute of Scientific and Technical Information of China (English)

    T.Nagayama; R.C.Mancini; D.Mayes; R.Tommasini; R.Florido

    2015-01-01

    Temperature and density asymmetry diagnosis is critical to advance inertial confinement fusion(ICF) science. A multimonochromatic x-ray imager, MMI, records the spectral signature from an ICF implosion core with time resolution, 2D spatial resolution and spectral resolution. While narrow-band images and 2D space-resolved spectra from the MMI data constrain the temperature and the density spatial structure of the core, the accuracy of the images and the spectra highly depends on the quality of the MMI data and the processing tools. Here, we synthetically investigate the criterion for reliable MMI diagnostics and its effects on the accuracy of the reconstructed images. The pinhole array tilt determines the object spatial sampling efficiency and the minimum reconstruction width, w. When the spectral width associated with w is significantly narrower than the spectral linewidth, the line images reconstructed from the MMI data become reliable. The MMI setup has to be optimized for every application to meet this criterion for reliable ICF diagnostics.

  2. Multi-stage 3D-2D registration for correction of anatomical deformation in image-guided spine surgery

    Science.gov (United States)

    Ketcha, M. D.; De Silva, T.; Uneri, A.; Jacobson, M. W.; Goerres, J.; Kleinszig, G.; Vogt, S.; Wolinsky, J.-P.; Siewerdsen, J. H.

    2017-06-01

    A multi-stage image-based 3D-2D registration method is presented that maps annotations in a 3D image (e.g. point labels annotating individual vertebrae in preoperative CT) to an intraoperative radiograph in which the patient has undergone non-rigid anatomical deformation due to changes in patient positioning or due to the intervention itself. The proposed method (termed msLevelCheck) extends a previous rigid registration solution (LevelCheck) to provide an accurate mapping of vertebral labels in the presence of spinal deformation. The method employs a multi-stage series of rigid 3D-2D registrations performed on sets of automatically determined and increasingly localized sub-images, with the final stage achieving a rigid mapping for each label to yield a locally rigid yet globally deformable solution. The method was evaluated first in a phantom study in which a CT image of the spine was acquired followed by a series of 7 mobile radiographs with increasing degree of deformation applied. Second, the method was validated using a clinical data set of patients exhibiting strong spinal deformation during thoracolumbar spine surgery. Registration accuracy was assessed using projection distance error (PDE) and failure rate (PDE  >  20 mm—i.e. label registered outside vertebra). The msLevelCheck method was able to register all vertebrae accurately for all cases of deformation in the phantom study, improving the maximum PDE of the rigid method from 22.4 mm to 3.9 mm. The clinical study demonstrated the feasibility of the approach in real patient data by accurately registering all vertebral labels in each case, eliminating all instances of failure encountered in the conventional rigid method. The multi-stage approach demonstrated accurate mapping of vertebral labels in the presence of strong spinal deformation. The msLevelCheck method maintains other advantageous aspects of the original LevelCheck method (e.g. compatibility with standard clinical workflow, large

  3. 2D image of local density and magnetic fluctuations from line-integrated interferometry-polarimetry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lin, L., E-mail: lianglin@ucla.edu; Ding, W. X.; Brower, D. L. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2014-11-15

    Combined polarimetry-interferometry capability permits simultaneous measurement of line-integrated density and Faraday effect with fast time response (∼1 μs) and high sensitivity. Faraday effect fluctuations with phase shift of order 0.05° associated with global tearing modes are resolved with an uncertainty ∼0.01°. For physics investigations, local density fluctuations are obtained by inverting the line-integrated interferometry data. The local magnetic and current density fluctuations are then reconstructed using a parameterized fit of the polarimetry data. Reconstructed 2D images of density and magnetic field fluctuations in a poloidal cross section exhibit significantly different spatial structure. Combined with their relative phase, the magnetic-fluctuation-induced particle transport flux and its spatial distribution are resolved.

  4. 2D image of local density and magnetic fluctuations from line-integrated interferometry-polarimetry measurements.

    Science.gov (United States)

    Lin, L; Ding, W X; Brower, D L

    2014-11-01

    Combined polarimetry-interferometry capability permits simultaneous measurement of line-integrated density and Faraday effect with fast time response (∼1 μs) and high sensitivity. Faraday effect fluctuations with phase shift of order 0.05° associated with global tearing modes are resolved with an uncertainty ∼0.01°. For physics investigations, local density fluctuations are obtained by inverting the line-integrated interferometry data. The local magnetic and current density fluctuations are then reconstructed using a parameterized fit of the polarimetry data. Reconstructed 2D images of density and magnetic field fluctuations in a poloidal cross section exhibit significantly different spatial structure. Combined with their relative phase, the magnetic-fluctuation-induced particle transport flux and its spatial distribution are resolved.

  5. Preliminary clinical results: an analyzing tool for 2D optical imaging in detection of active inflammation in rheumatoid arthritis

    Science.gov (United States)

    Adi Aizudin Bin Radin Nasirudin, Radin; Meier, Reinhard; Ahari, Carmen; Sievert, Matti; Fiebich, Martin; Rummeny, Ernst J.; No"l, Peter B.

    2011-03-01

    Optical imaging (OI) is a relatively new method in detecting active inflammation of hand joints of patients suffering from rheumatoid arthritis (RA). With the high number of people affected by this disease especially in western countries, the availability of OI as an early diagnostic imaging method is clinically highly relevant. In this paper, we present a newly in-house developed OI analyzing tool and a clinical evaluation study. Our analyzing tool extends the capability of existing OI tools. We include many features in the tool, such as region-based image analysis, hyper perfusion curve analysis, and multi-modality image fusion to aid clinicians in localizing and determining the intensity of inflammation in joints. Additionally, image data management options, such as the full integration of PACS/RIS, are included. In our clinical study we demonstrate how OI facilitates the detection of active inflammation in rheumatoid arthritis. The preliminary clinical results indicate a sensitivity of 43.5%, a specificity of 80.3%, an accuracy of 65.7%, a positive predictive value of 76.6%, and a negative predictive value of 64.9% in relation to clinical results from MRI. The accuracy of inflammation detection serves as evidence to the potential of OI as a useful imaging modality for early detection of active inflammation in patients with rheumatoid arthritis. With our in-house developed tool we extend the usefulness of OI imaging in the clinical arena. Overall, we show that OI is a fast, inexpensive, non-invasive and nonionizing yet highly sensitive and accurate imaging modality.-

  6. Estimation and application of 2-D scattering matrices for sparse array imaging of simulated damage in composite panels

    Science.gov (United States)

    Williams, Westin B.; Michaels, Thomas E.; Michaels, Jennifer E.

    2017-02-01

    Reliable detection of damage in composites is critically important for failure prevention in the aerospace industry since these materials are more frequently being used in high stress applications. Structural health monitoring (SHM) via guided wave sensors mounted on or embedded within a composite structure can help detect and localize damage in real-time while potentially reducing overall maintenance costs. One approach to guided wave SHM is sparse array imaging via the minimum variance algorithm, and it has been shown in prior work that incorporating expected scattering from defects of interest can improve the quality of damage localization and characterization. For this study, simulated damage in the form of attached magnets was used for estimating scattering from recorded wavefield data. Data were recorded on a circle centered at the damage location from multiple incident directions before and after the magnets were attached. Baseline subtraction is used to estimate scattering patterns for each incident direction, and these patterns are combined and interpolated to form a full 2-D scattering matrix. This matrix is then incorporated into the minimum variance imaging algorithm, and the efficacy of this scattering estimation methodology is evaluated by comparing the resulting sparse array images to those generated using simpler scattering assumptions.

  7. Automatic Measurement of Thalamic Diameter in 2-D Fetal Ultrasound Brain Images Using Shape Prior Constrained Regularized Level Sets.

    Science.gov (United States)

    Sridar, Pradeeba; Kumar, Ashnil; Li, Changyang; Woo, Joyce; Quinton, Ann; Benzie, Ron; Peek, Michael J; Feng, Dagan; Kumar, R Krishna; Nanan, Ralph; Kim, Jinman

    2017-07-01

    We derived an automated algorithm for accurately measuring the thalamic diameter from 2-D fetal ultrasound (US) brain images. The algorithm overcomes the inherent limitations of the US image modality: nonuniform density; missing boundaries; and strong speckle noise. We introduced a "guitar" structure that represents the negative space surrounding the thalamic regions. The guitar acts as a landmark for deriving the widest points of the thalamus even when its boundaries are not identifiable. We augmented a generalized level-set framework with a shape prior and constraints derived from statistical shape models of the guitars; this framework was used to segment US images and measure the thalamic diameter. Our segmentation method achieved a higher mean Dice similarity coefficient, Hausdorff distance, specificity, and reduced contour leakage when compared to other well-established methods. The automatic thalamic diameter measurement had an interobserver variability of -0.56 ± 2.29 mm compared to manual measurement by an expert sonographer. Our method was capable of automatically estimating the thalamic diameter, with the measurement accuracy on par with clinical assessment. Our method can be used as part of computer-assisted screening tools that automatically measure the biometrics of the fetal thalamus; these biometrics are linked to neurodevelopmental outcomes.

  8. Cost-effectiveness modelling in diagnostic imaging: a stepwise approach

    NARCIS (Netherlands)

    Sailer, A.M.; Zwam, W.H. van; Wildberger, J.E.; Grutters, J.P.C.

    2015-01-01

    Diagnostic imaging (DI) is the fastest growing sector in medical expenditures and takes a central role in medical decision-making. The increasing number of various and new imaging technologies induces a growing demand for cost-effectiveness analysis (CEA) in imaging technology assessment. In this ar

  9. Effect of image processing version on detection of non-calcification cancers in 2D digital mammography imaging

    Science.gov (United States)

    Warren, L. M.; Cooke, J.; Given-Wilson, R. M.; Wallis, M. G.; Halling-Brown, M.; Mackenzie, A.; Chakraborty, D. P.; Bosmans, H.; Dance, D. R.; Young, K. C.

    2013-03-01

    Image processing (IP) is the last step in the digital mammography imaging chain before interpretation by a radiologist. Each manufacturer has their own IP algorithm(s) and the appearance of an image after IP can vary greatly depending upon the algorithm and version used. It is unclear whether these differences can affect cancer detection. This work investigates the effect of IP on the detection of non-calcification cancers by expert observers. Digital mammography images for 190 patients were collected from two screening sites using Hologic amorphous selenium detectors. Eighty of these cases contained non-calcification cancers. The images were processed using three versions of IP from Hologic - default (full enhancement), low contrast (intermediate enhancement) and pseudo screen-film (no enhancement). Seven experienced observers inspected the images and marked the location of regions suspected to be non-calcification cancers assigning a score for likelihood of malignancy. This data was analysed using JAFROC analysis. The observers also scored the clinical interpretation of the entire case using the BSBR classification scale. This was analysed using ROC analysis. The breast density in the region surrounding each cancer and the number of times each cancer was detected were calculated. IP did not have a significant effect on the radiologists' judgment of the likelihood of malignancy of individual lesions or their clinical interpretation of the entire case. No correlation was found between number of times each cancer was detected and the density of breast tissue surrounding that cancer.

  10. Detection of mullerian duct anomalies: diagnostic utility of two dimensional ultrasonography as compared to magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Krishna Pratap Singh Senger

    2016-12-01

    Full Text Available Background: Mullerian duct anomalies (MDAs are a fascinating group of disorders that have varied clinical presentation from being asymptomatic to primary amenorrhea to inability to reproduce. Correct diagnosis of the condition plays a crucial role in management. Imaging plays a pivotal role in making correct diagnosis. This study aims to find the prevalence of MDAs amongst study population and their relation with infertility and also compares diagnostic utility of pelvic ultrasound with MRI. Methods: A randomized diagnostic test evaluation study was conducted in the Department of Radiodiagnosis and Imaging of a tertiary care teaching hospital over a period of 2 years. The patient first underwent pelvic 2D USG in multiple planes using curvilinear probe of 3MHz to 5 MHz. frequency and then MRI. Results: Most common MDA in total study sample and in primary infertility group is arcuate uterus while in recurrent abortions group it is unicornuate uterus. Out of total study sample of 75 patients 2D USG detected 18 cases of MDA while MRI detected 22 cases of MDA. So, 2D USG failed to detect 04 cases of MDA in total study population bringing overall sensitivity of 2D USG as 81.8%, specificity of 100%, PPV of 100%, NPV of 93.4% and accuracy of 94.6%. Conclusions: 2D USG has a few limitations but in view of relatively simple imaging procedure, ease of availability and cost effectiveness it should be utilized as an initial imaging modality in patients with suspicion of MDAs.

  11. Optimisation of patient protection and image quality in diagnostic ...

    African Journals Online (AJOL)

    Optimisation of patient protection and image quality in diagnostic radiology. ... The study leads to the introduction of the concept of plan- do-check-act on QC results ... (QA) programme and continues to collect data for establishment of DRL's.

  12. Imaging Agonist-Induced D2/D3 Receptor Desensitization and Internalization In Vivo with PET/fMRI.

    Science.gov (United States)

    Sander, Christin Y; Hooker, Jacob M; Catana, Ciprian; Rosen, Bruce R; Mandeville, Joseph B

    2016-04-01

    This study investigated the dynamics of dopamine receptor desensitization and internalization, thereby proposing a new technique for non-invasive, in vivo measurements of receptor adaptations. The D2/D3 agonist quinpirole, which induces receptor internalization in vitro, was administered at graded doses in non-human primates while imaging with simultaneous positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). A pronounced temporal divergence between receptor occupancy and fMRI signal was observed: occupancy remained elevated while fMRI responded transiently. Analogous experiments with an antagonist (prochlorperazine) and a lower-affinity agonist (ropinirole) exhibited reduced temporal dissociation between occupancy and function, consistent with a mechanism of desensitization and internalization that depends upon drug efficacy and affinity. We postulated a model that incorporates internalization into a neurovascular-coupling relationship. This model yielded in vivo desensitization/internalization rates (0.2/min for quinpirole) consistent with published in vitro measurements. Overall, these results suggest that simultaneous PET/fMRI enables characterization of dynamic neuroreceptor adaptations in vivo, and may offer a first non-invasive method for assessing receptor desensitization and internalization.

  13. WASI-2D: A software tool for regionally optimized analysis of imaging spectrometer data from deep and shallow waters

    Science.gov (United States)

    Gege, Peter

    2014-01-01

    An image processing software has been developed which allows quantitative analysis of multi- and hyperspectral data from oceanic, coastal and inland waters. It has been implemented into the Water Colour Simulator WASI, which is a tool for the simulation and analysis of optical properties and light field parameters of deep and shallow waters. The new module WASI-2D can import atmospherically corrected images from airborne sensors and satellite instruments in various data formats and units like remote sensing reflectance or radiance. It can be easily adapted by the user to different sensors and to optical properties of the studied area. Data analysis is done by inverse modelling using established analytical models. The bio-optical model of the water column accounts for gelbstoff (coloured dissolved organic matter, CDOM), detritus, and mixtures of up to 6 phytoplankton classes and 2 spectrally different types of suspended matter. The reflectance of the sea floor is treated as sum of up to 6 substrate types. An analytic model of downwelling irradiance allows wavelength dependent modelling of sun glint and sky glint at the water surface. The provided database covers the spectral range from 350 to 1000 nm in 1 nm intervals. It can be exchanged easily to represent the optical properties of water constituents, bottom types and the atmosphere of the studied area.

  14. Imaging 2D structures by the CSAMT method: application to the Pantano di S. Gregorio Magno faulted basin (Southern Italy)

    Science.gov (United States)

    Troiano, Antonio; Di Giuseppe, Maria Giulia; Petrillo, Zaccaria; Patella, Domenico

    2009-06-01

    A controlled source audiofrequency magnetotelluric (CSAMT) survey has been undertaken in the Pantano di San Gregorio Magno faulted basin, an earthquake prone area of Southern Apennines in Italy. A dataset from 11 soundings, distributed along a nearly N-S 780 m long profile, was acquired in the basin's easternmost area, where the fewest data are available as to the faulting shallow features. A preliminary skew analysis allowed a prevailing 2D nature of the dataset to be ascertained. Then, using a single-site multi-frequency approach, Dantzig's simplex algorithm was introduced for the first time to estimate the CSAMT decomposition parameters. The simplex algorithm, freely available online, proved to be fast and efficient. By this approach, the TM and TE mode field diagrams were obtained and a N35°W ± 10° 2D strike mean direction was estimated along the profile, in substantial agreement with the fault traces within the basin. A 2D inversion of the apparent resistivity and phase curves at seven almost noise-free sites distributed along the central portion of the profile was finally elaborated, reinforced by a sensitivity analysis, which allowed the best resolved portion of the model to be imaged from the first few meters of depth down to a mean depth of 300 m b.g.l. From the inverted section, the following features have been outlined: (i) a cover layer with resistivity in the range 3-30 Ω m ascribed to the Quaternary lacustrine clayey deposits filling the basin, down to an average depth of about 35 m b.g.l., underlain by a structure with resistivity over 50 Ω m up to about 600 Ω m, ascribed to the Mesozoic carbonate bedrock; (ii) a system of two normal faults within the carbonate basement, extending down to the maximum best resolved depth of the order of 300 m b.g.l.; (iii) two wedge-shaped domains separating the opposite blocks of the faults with resistivity ranging between 30 Ω m and 50 Ω m and horizontal extent of the order of some tens of metres, likely

  15. Quantification of tracer plume transport parameters in 2D saturated porous media by cross-borehole ERT imaging

    Science.gov (United States)

    Lekmine, G.; Auradou, H.; Pessel, M.; Rayner, J. L.

    2017-04-01

    Cross-borehole ERT imaging was tested to quantify the average velocity and transport parameters of tracer plumes in saturated porous media. Seven tracer tests were performed at different flow rates and monitored by either a vertical or horizontal dipole-dipole ERT sequence. These sequences were tested to reconstruct the shape and temporally follow the spread of the tracer plumes through a background regularization procedure. Data sets were inverted with the same inversion parameters and 2D model sections of resistivity ratios were converted to tracer concentrations. Both array types provided an accurate estimation of the average pore velocity vz. The total mass Mtot recovered was always overestimated by the horizontal dipole-dipole and underestimated by the vertical dipole-dipole. The vertical dipole-dipole was however reliable to quantify the longitudinal dispersivity λz, while the horizontal dipole-dipole returned better estimation for the transverse component λx. λ and Mtot were mainly influenced by the 2D distribution of the cumulated electrical sensitivity and the Shadow Effects induced by the third dimension. The size reduction of the edge of the plume was also related to the inability of the inversion process to reconstruct sharp resistivity contrasts at the interface. Smoothing was counterbalanced by a non-realistic rise of the ERT concentrations around the centre of mass returning overpredicted total masses. A sensitivity analysis on the cementation factor m and the porosity ϕ demonstrated that a change in one of these parameters by 8% involved non negligible variations by 30 and 40% of the dispersion coefficients and mass recovery.

  16. Comparing an accelerated 3D fast spin-echo sequence (CS-SPACE) for knee 3-T magnetic resonance imaging with traditional 3D fast spin-echo (SPACE) and routine 2D sequences

    Energy Technology Data Exchange (ETDEWEB)

    Altahawi, Faysal F.; Blount, Kevin J.; Omar, Imran M. [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Morley, Nicholas P. [Marshfield Clinic, Department of Radiology, Marshfield, WI (United States); Raithel, Esther [Siemens Healthcare GmbH, Erlangen (Germany)

    2017-01-15

    To compare a faster, new, high-resolution accelerated 3D-fast-spin-echo (3D-FSE) acquisition sequence (CS-SPACE) to traditional 2D and high-resolution 3D sequences for knee 3-T magnetic resonance imaging (MRI). Twenty patients received knee MRIs that included routine 2D (T1, PD ± FS, T2-FS; 0.5 x 0.5 x 3 mm{sup 3}; ∝10 min), traditional 3D FSE (SPACE-PD-FS; 0.5 x 0.5 x 0.5 mm{sup 3}; ∝7.5 min), and accelerated 3D-FSE prototype (CS-SPACE-PD-FS; 0.5 x 0.5 x 0.5 mm{sup 3}; ∝5 min) acquisitions on a 3-T MRI system (Siemens MAGNETOM Skyra). Three musculoskeletal radiologists (MSKRs) prospectively and independently reviewed the studies with graded surveys comparing image and diagnostic quality. Tissue-specific signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were also compared. MSKR-perceived diagnostic quality of cartilage was significantly higher for CS-SPACE than for SPACE and 2D sequences (p < 0.001). Assessment of diagnostic quality of menisci and synovial fluid was higher for CS-SPACE than for SPACE (p < 0.001). CS-SPACE was not significantly different from SPACE but had lower assessments than 2D sequences for evaluation of bones, ligaments, muscles, and fat (p ≤ 0.004). 3D sequences had higher spatial resolution, but lower overall assessed contrast (p < 0.001). Overall image quality from CS-SPACE was assessed as higher than SPACE (p = 0.007), but lower than 2D sequences (p < 0.001). Compared to SPACE, CS-SPACE had higher fluid SNR and CNR against all other tissues (all p < 0.001). The CS-SPACE prototype allows for faster isotropic acquisitions of knee MRIs over currently used protocols. High fluid-to-cartilage CNR and higher spatial resolution over routine 2D sequences may present a valuable role for CS-SPACE in the evaluation of cartilage and menisci. (orig.)

  17. Individual recognition in domestic cattle (Bos taurus: evidence from 2D-images of heads from different breeds.

    Directory of Open Access Journals (Sweden)

    Marjorie Coulon

    Full Text Available BACKGROUND: In order to maintain cohesion of groups, social animals need to process social information efficiently. Visual individual recognition, which is distinguished from mere visual discrimination, has been studied in only few mammalian species. In addition, most previous studies used either a small number of subjects or a few various views as test stimuli. Dairy cattle, as a domestic species allow the testing of a good sample size and provide a large variety of test stimuli due to the morphological diversity of breeds. Hence cattle are a suitable model for studying individual visual recognition. This study demonstrates that cattle display visual individual recognition and shows the effect of both familiarity and coat diversity in discrimination. METHODOLOGY/PRINCIPAL FINDINGS: We tested whether 8 Prim'Holstein heifers could recognize 2D-images of heads of one cow (face, profiles, (3/4 views from those of other cows. Experiments were based on a simultaneous discrimination paradigm through instrumental conditioning using food rewards. In Experiment 1, all images represented familiar cows (belonging to the same social group from the Prim'Holstein breed. In Experiments 2, 3 and 4, images were from unfamiliar (unknown individuals either from the same breed or other breeds. All heifers displayed individual recognition of familiar and unfamiliar individuals from their own breed. Subjects reached criterion sooner when recognizing a familiar individual than when recognizing an unfamiliar one (Exp 1: 3.1+/-0.7 vs. Exp 2: 5.2+/-1.2 sessions; Z = 1.99, N = 8, P = 0.046. In addition almost all subjects recognized unknown individuals from different breeds, however with greater difficulty. CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that cattle have efficient individual recognition based on categorization capacities. Social familiarity improved their performance. The recognition of individuals with very different coat characteristics from the

  18. A survey of medical diagnostic imaging technologies

    Energy Technology Data Exchange (ETDEWEB)

    Heese, V.; Gmuer, N.; Thomlinson, W.

    1991-10-01

    The fields of medical imaging and medical imaging instrumentation are increasingly important. The state-of-the-art continues to advance at a very rapid pace. In fact, various medical imaging modalities are under development at the National Synchrotron Light Source (such as MECT and Transvenous Angiography.) It is important to understand how these techniques compare with today's more conventional imaging modalities. The purpose of this report is to provide some basic information about the various medical imaging technologies currently in use and their potential developments as a basis for this comparison. This report is by no means an in-depth study of the physics and instrumentation of the various imaging modalities; instead, it is an attempt to provide an explanation of the physical bases of these techniques and their principal clinical and research capabilities.

  19. A survey of medical diagnostic imaging technologies

    Energy Technology Data Exchange (ETDEWEB)

    Heese, V.; Gmuer, N.; Thomlinson, W.

    1991-10-01

    The fields of medical imaging and medical imaging instrumentation are increasingly important. The state-of-the-art continues to advance at a very rapid pace. In fact, various medical imaging modalities are under development at the National Synchrotron Light Source (such as MECT and Transvenous Angiography.) It is important to understand how these techniques compare with today`s more conventional imaging modalities. The purpose of this report is to provide some basic information about the various medical imaging technologies currently in use and their potential developments as a basis for this comparison. This report is by no means an in-depth study of the physics and instrumentation of the various imaging modalities; instead, it is an attempt to provide an explanation of the physical bases of these techniques and their principal clinical and research capabilities.

  20. 2D-gel spot detection and segmentation based on modified image-aware grow-cut and regional intensity information.

    Science.gov (United States)

    Kostopoulou, E; Katsigiannis, S; Maroulis, D

    2015-10-01

    Proteomics, the study of proteomes, has been increasingly utilized in a wide variety of biological problems. The Two-Dimensional Gel Electrophoresis (2D-PAGE) technique is a powerful proteomics technique aiming at separation of the complex protein mixtures. Spot detection and segmentation are fundamental components of 2D-gel image analysis but remain arduous and difficult tasks. Several software packages and academic approaches are available for 2D-gel image spot detection and segmentation. Each one has its respective advantages and disadvantages and achieves a different level of success in dealing with the challenges of 2D-gel image analysis. A common characteristic of the available methods is their dependency on user intervention in order to achieve optimal results, a process that can lead to subjective and non-reproducible results. In this work, the authors propose a novel spot detection and segmentation methodology for 2D-gel images. This work introduces a novel spot detection and spot segmentation methodology that is based on a multi-thresholding scheme applied on overlapping regions of the image, a custom grow-cut algorithm, a region growing scheme and morphological operators. The performance of the proposed methodology is evaluated on real as well as synthetic 2D-gel images using well established statistical measures, including precision, sensitivity, and their weighted measure, F-measure, as well as volumetric overlap, volumetric error and volumetric overlap error. Experimental results show that the proposed methodology outperforms state-of-the-art software packages and methods proposed in the literature and results in more plausible spot boundaries and more accurate segmentation. The proposed method achieved the highest F-measure (94.8%) for spot detection and the lowest volumetric overlap error (8.3%) for the segmentation process. Evaluation against state-of-the-art 2D-gel image analysis software packages and techniques proposed in the literature

  1. Images of Gravitational and Magnetic Phenomena Derived from 2D Back-Projection Doppler Tomography of Interacting Binary Stars

    CERN Document Server

    Richards, Mercedes T; Fisher, John G; Conover, Marshall J

    2014-01-01

    We have used 2D back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries which undergo mass transfer from a magnetically-active star onto a non-magnetic main sequence star. This multi-tiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The H$\\alpha$ tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several me...

  2. Simultaneous 2D imaging of dissolved iron and reactive phosphorus in sediment porewaters by thin-film and hyperspectral methods.

    Science.gov (United States)

    Cesbron, Florian; Metzger, Edouard; Launeau, Patrick; Deflandre, Bruno; Delgard, Marie-Lise; Thibault de Chanvalon, Aubin; Geslin, Emmanuelle; Anschutz, Pierre; Jézéquel, Didier

    2014-01-01

    This study presents a new approach combining diffusive equilibrium in thin-film (DET) and spectrophotometric methods to determine the spatial variability of dissolved iron and dissolved reactive phosphorus (DRP) with a single gel probe. Its originality is (1) to postpone up to three months the colorimetric reaction of DET by freezing and (2) to measure simultaneously dissolved iron and DRP by hyperspectral imaging at a submillimeter resolution. After a few minutes at room temperature, the thawed gel is sandwiched between two monospecific reagent DET gels, leading to magenta and blue coloration for iron and phosphate, respectively. Spatial distribution of the resulting colors is obtained using a hyperspectral camera. Reflectance spectra analysis enables deconvolution of specific colorations by the unmixing method applied to the logarithmic reflectance, leading to an accurate quantification of iron and DRP. This method was applied in the Arcachon lagoon (France) on muddy sediments colonized by eelgrass (Zostera noltei) meadows. The 2D gel probes highlighted microstructures in the spatial distribution of dissolved iron and phosphorus, which are most likely associated with the occurrence of benthic fauna burrows and seagrass roots.

  3. Constraining Polarized Foregrounds for EoR Experiments I: 2D Power Spectra from the PAPER-32 Imaging Array

    CERN Document Server

    Kohn, S A; Nunhokee, C; Bernardi, G; Pober, J; Ali, Z; Bradley, R; Carilli, C; DeBoer, D; Gugliucci, N; Jacobs, D; Klima, P; MacMahon, D; Manley, J; Moore, D; Parsons, A; Stefan, I; Walbrugh, W

    2016-01-01

    Current-generation low frequency interferometers constructed with the objective of detecting the high-redshift 21 cm background, aim to generate power spectra of the brightness-temperature contrast of neutral hydrogen in primordial intergalactic medium. Two-dimensional power spectra (power in Fourier modes parallel and perpendicular to the line of sight) formed from interferometric visibilities have been shown to delineate a boundary between spectrally-smooth foregrounds (known as the wedge) and spectrally-structured 21 cm background emission (the EoR-window). However, polarized foregrounds are known to possess spectral structure due to Faraday rotation, which can leak into the EoR window. In this work, we create and analyze 2D power spectra from the PAPER-32 imaging array in Stokes I, Q, U and V. These allow us to observe and diagnose systematic effects in our calibration at high signal-to-noise within the Fourier space most relevant to EoR experiments. We observe well-defined windows in the Stokes visibilit...

  4. Radiation exposure from diagnostic imaging among patients with gastrointestinal disorders.

    LENUS (Irish Health Repository)

    Desmond, Alan N

    2012-03-01

    There are concerns about levels of radiation exposure among patients who undergo diagnostic imaging for inflammatory bowel disease (IBD), compared with other gastrointestinal (GI) disorders. We quantified imaging studies and estimated the cumulative effective dose (CED) of radiation received by patients with organic and functional GI disorders. We also identified factors and diagnoses associated with high CEDs.

  5. The Application of 2D/3D Rigid Image Registration in Tumor Radiation Treatment Planning%2D/3D刚性图像配准在肿瘤放疗计划中的应用

    Institute of Scientific and Technical Information of China (English)

    李欣; 周凌宏; 甄鑫; 卢文婷

    2011-01-01

    目的:在肿瘤放疗中,2D/3D刚性图像配准技术是精确定位病人重要保证.方法:数字重建放射影像技术是2D/3D配准中最为关键的部分,一定程度上影响着配准效率.在对数字重建放射影像进行重点研究的基础上,实现了一种基于Bresenham方法的快速数字影像重建算法,并利用腹部CT体数据进行了2D/3D配准实验.实验以互信息、模式强度和梯度差分为相似性测度并采用了Powell-Brent优化算法.结果:在数字重建放射图像算法实验中,Bresemham方法相比于另外两种光线跟踪算法,时间仅需0.467 s.在2D/3D配准实验中,对三种相似性测度的实验结果进行了比较,互信息和梯度差分有较好的配准结果,模式强度仍存在不少问题.结论:实验结果表明,利用Bresenham方法产生的数字重建影像能使得配准具有较高精度,但配准时间仍然较长.%Objective: The technique of 2D/3D rigid image registration is critical to ensure accurately positioning of patients in radiation therapy. Methods: Digitally reconstructed radiographs (DRRs) played the most important pole in 2D/3D registration,which affected the registration efficiency in some way. On the basis of special researches about DRRs, the authors realized a fast DRRs algorithm based on Bresenham method. Various 2D/3D registration experiments were carried out on abdomen CT volume data. Mutual information, Pattem Intensity, Gradient Difference and Powell-Brent algorithm were used as similarity measurement and search strategy in the experiments, respectively. Results: In DRRs algorithms, compared with the two other methods, Bresenham method has time of 0.467 s. In 2D/3D image registration experiment, the results of three similarities are compared. MI and GD have an excellent performance; however, there are some problems in PI' s experiment. Conclusions: The results show that the registration algorithm utilizing Bresenham method to generate DRRs has a great

  6. Watching Silica's Dance: Imaging the Structure and Dynamics of the Atomic (Re-) Arrangements in 2D Glass

    Science.gov (United States)

    Muller, David

    2014-03-01

    Even though glasses are almost ubiquitous--in our windows, on our iPhones, even on our faces--they are also mysterious. Because glasses are notoriously difficult to study, basic questions like: ``How are the atoms arranged? Where and how do glasses break?'' are still under contention. We use aberration corrected transmission electron microscopy (TEM) to image the atoms in a new two-dimensional phase of silica glass - freestanding it becomes the world's thinnest pane of glass at only 3-atoms thick, and take a unique look into these questions. Using atom-by-atom imaging and spectroscopy, we are able to reconstruct the full structure and bonding of this 2D glass and identify it as a bi-tetrahedral layer of SiO2. Our images also strikingly resemble Zachariasen's original cartoon models of glasses, drawn in 1932. As such, our work realizes an 80-year-old vision for easily understandable glassy systems and introduces promising methods to test theoretical predictions against experimental data. We image atoms in the disordered solid and track their motions in response to local strain. We directly obtain ring statistics and pair distribution functions that span short-, medium-, and long-range order, and test these against long-standing theoretical predictions of glass structure and dynamics. We use the electron beam to excite atomic rearrangements, producing surprisingly rich and beautiful videos of how a glass bends and breaks, as well as the exchange of atoms at a solid/liquid interface. Detailed analyses of these videos reveal a complex dance of elastic and plastic deformations, phase transitions, and their interplay. These examples illustrate the wide-ranging and fundamental materials physics that can now be studied at atomic-resolution via transmission electron microscopy of two-dimensional glasses. Work in collaboration with: S. Kurasch, U. Kaiser, R. Hovden, Q. Mao, J. Kotakoski, J. S. Alden, A. Shekhawat, A. A. Alemi, J. P. Sethna, P. L. McEuen, A.V. Krasheninnikov

  7. An automated technique for potential differentiation of ovarian mature teratomas from other benign tumours using neural networks classification of 2D ultrasound static images: a pilot study

    Science.gov (United States)

    Al-karawi, Dhurgham; Sayasneh, A.; Al-Assam, Hisham; Jassim, Sabah; Page, N.; Timmerman, D.; Bourne, T.; Du, Hongbo

    2017-05-01

    Ovarian cysts are a common pathology in women of all age groups. It is estimated that 5-10% of women have a surgical intervention to remove an ovarian cyst in their lifetime. Given this frequency rate, characterization of ovarian masses is essential for optimal management of patients. Patients with benign ovarian masses can be managed conservatively if they are asymptomatic. Mature teratomas are common benign ovarian cysts that occur, in most cases, in premenopausal women. These ovarian cysts can contain different types of human tissue including bone, cartilage, fat, hair, or other tissue. If they are causing no symptoms, they can be harmless and may not require surgery. Subjective assessment by ultrasound examiners has a high diagnostic accuracy when characterising mature teratomas from other types of tumours. The aim of this study is to develop a computerised technique with the potential to characterise mature teratomas and distinguish them from other types of benign ovarian tumours. Local Binary Pattern (LBP) was applied to extract texture features that are specific in distinguishing teratomas. Neural Networks (NN) was then used as a classifier for recognising mature teratomas. A pilot sample set of 130 B-mode static ovarian ultrasound images (41 mature teratomas tumours and 89 other types of benign tumours) was used to test the effectiveness of the proposed technique. Test results show an average accuracy rate of 99.4% with a sensitivity of 100%, specificity of 98.8% and positive predictive value of 98.9%. This study demonstrates that the NN and LBP techniques can accurately classify static 2D B-mode ultrasound images of benign ovarian masses into mature teratomas and other types of benign tumours.

  8. EFFECTS OF ELECTRODE SPACING AND INVERSION TECHNIQUES ON THE EFFICACY OF 2D RESISTIVITY IMAGING TO DELINEATE SUBSURFACE FEATURES

    Directory of Open Access Journals (Sweden)

    Adiat Kola Abdul-Nafiu

    2013-01-01

    Full Text Available In this study, the effect of the choice of appropriate electrode spacing and inversion algorithms on the efficacy of 2D imaging to map subsurface features was investigated. The target being investigated was the drainage concrete pipe buried at approximately 0.3 m into the subsurface. A profile perpendicular to the strike of the pipe was established. 2D resistivity data was separately collected with the electrode spacings of 1.5 m and 0.5 m. using the Dipole-Dipole, the Wenner and the Wenner-Schlumberger array configurations. The results obtained showed that when the electrode spacing of 1.5 m was used for the investigations, none of the three array types was able to map the target with either of the two inversion techniques. The results further show that the attainment of RMS error of less about 10% which usually gives the indication of a good subsurface model is not a guarantee that subsurface features are successfully mapped. On the other hand, when the electrode spacing of 0.5 m was used for the data collection, the results obtained with the standard constrains inversion technique showed that all the three array configurations mapped the target however, only the dipole-dipole array was able to resolve the boundary between the concrete pipe and the entrapped air. With the robust constrain inversion technique; the target was also successfully mapped by all the three array types. In addition to this, the boundary between the entrapped air and the concrete pipe was resolved by all the three array types. This suggests that if there is a significant contrast in the subsurface layers’ resistivities, the robust constrain inversion algorithm technique gives better boundaries resolution irrespective of the array types used for the survey. The inversion of the 3D data gave 3D resistivity sections which were presented as horizontal depth slices. The result obtained from the inversion of the 3D data has assisted us in getting information about the

  9. Using Integrated 2D and 3D Resistivity Imaging Methods for Illustrating the Mud-Fluid Conduits of the Wushanting Mud Volcanoes in Southwestern Taiwan

    Directory of Open Access Journals (Sweden)

    Ping-Yu Chang

    2011-01-01

    Full Text Available We conducted 2D and 3D looped resistivity surveys in the Wushanting Natural Landscape Preservation Area (WNLPA in order to understand the relationships of the mud-fluid conduits in the mud volcano system. 2D resistivity surveys were conducted along seven networked lines. Two separate C-shape looped electrode arrays surrounding the volcano craters were used in the study. First, the two 3D looped measurements were inverted separately. Yet the inverted 3D images of the mud-volcano system were inconsistent with the landscape features suggesting that artifacts perhaps appeared in the images. The 3D looped data were then combined with the 2D data for creating a global resistivity model of WNLPA. The resulting 3D image is consistent with the observed landscape features. With the resistivity model of WNLPA, we further tried to estimate the distribution of water content. The results suggest that the 3D resistivity image has the potential to resolve the dual porosity structures in the mudstone area. Last, we used a simplified WNLPA model for forward simulation in order to verify the field measurement results. We have concluded that the artifacts in the 3D looped images are in fact shadow effects from conductive objects out of the electrode loops, and that inverted images of combined 2D and 3D data provide detailed regional conductive structures in the WNLPA site.

  10. Diagnostic imaging analysis of the impacted mesiodens

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Jeong Jun; Choi, Bo Ram; Jeong, Hwan Seok; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2010-06-15

    The research was performed to predict the three dimensional relationship between the impacted mesiodens and the maxillary central incisors and the proximity with the anatomic structures by comparing their panoramic images with the CT images. Among the patients visiting Seoul National University Dental Hospital from April 2003 to July 2007, those with mesiodens were selected (154 mesiodens of 120 patients). The numbers, shapes, orientation and positional relationship of mesiodens with maxillary central incisors were investigated in the panoramic images. The proximity with the anatomical structures and complications were investigated in the CT images as well. The sex ratio (M : F) was 2.28 : 1 and the mean number of mesiodens per one patient was 1.28. Conical shape was 84.4% and inverted orientation was 51.9%. There were more cases of anatomical structures encroachment, especially on the nasal floor and nasopalatine duct, when the mesiodens was not superimposed with the central incisor. There were, however, many cases of the nasopalatine duct encroachment when the mesiodens was superimpoised with the apical 1/3 of central incisor (52.6%). Delayed eruption (55.6%), crown rotation (66.7%) and crown resorption (100%) were observed when the mesiodens was superimposed with the crown of the central incisor. It is possible to predict three dimensional relationship between the impacted mesiodens and the maxillary central incisors in the panoramic images, but more details should be confirmed by the CT images when necessary.

  11. DIAGNOSTIC IMAGING OF THE THROWING ATHLETE’S SHOULDER

    OpenAIRE

    Malone, Terry; Hazle, Charles

    2013-01-01

    The diagnostic capabilities of advanced imaging have increasingly enabled clinicians to delineate between structural alterations and injuries more efficiently than ever before. These impressive gains have unfortunately begun to provide a reliance on imaging at the loss of quality in the clinical examination. Ideally, imaging of the shoulder complex is performed to confirm the provisional diagnosis developed from the history and clinical exam rather than to create such. This clinical commentar...

  12. Verification of optical diagnostic methods in H{sub 2}/D{sub 2} - plasmas; Verifikation von optischen Diagnostikmethoden an H{sub 2}/D{sub 2} - Plasmen

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, Stephan

    2010-12-02

    For the neutral beam injection of the fusion experiment ITER negative deuterium ions have to be extracted from an ion source, accelerated to 1 MeV and subsequently neutralized. To control the plasma processes of the non-thermal hydrogen low temperature plasmas in the ion sources the knowledge of the plasma parameters like electron temperature and electron density is necessary. Among the required diagnostic methods the optical emission spectroscopy has one of the simplest setups which allows non-invasive and in situ measurements of the parameters. Within the scope of this thesis a modular diode system was developed, which allows together with systematically verified and improved optical diagnostic methods a time resolved online monitoring of the plasma parameters. The verification was carried out in stable and reproducible electron cyclotron resonance plasmas. These plasmas allows a simple comparison between the optical emission spectroscopy and various reference methods in a large parameter range of electron temperature and electron density. In order to verify the effective population densities from collisional radiative models and the deduced emission rate coefficients reference measurements were carried out using a Langmuir probe, a double probe, the Boyd-Twiddy-Method, interferometry, laser detachment, a mass spectrometer and already verified optical diagnostic methods of diagnostic gases like helium and argon. By a correction of the used collisional radiative model the determination of the electron density was significantly improved. (orig.)

  13. MR imaging features of idiopathic thoracic spinal cord herniations using combined 3D-fiesta and 2D-PC Cine techniques.

    Science.gov (United States)

    Ferré, J C; Carsin-Nicol, B; Hamlat, A; Carsin, M; Morandi, X

    2005-03-01

    Idiopathic thoracic spinal cord herniation (TISCH) is a rare cause of surgically treatable progressive myelopathy. The authors report 3 cases of TISCH diagnosed based on conventional T1- and T2-weighted Spin-Echo (SE) MR images in one case, and T1- and T2-weighted SE images combined with 3D-FIESTA (Fast Imaging Employing Steady state Acquisition) and 2D-Phase-Contrast Cine MR imaging in 2 cases. Conventional MRI findings usually provided the diagnosis. 3D-FIESTA images confirmed it, showing the herniated cord in the ventral epidural space. Moreover, in combination with 2D-Phase Contrast cine technique, it was a sensitive method to for the detection of associated pre- or postoperative cerebrospinal fluid spaces abnormalities.

  14. A Rapid and Efficient 2D/3D Nuclear Segmentation Method for Analysis of Early Mouse Embryo and Stem Cell Image Data

    Directory of Open Access Journals (Sweden)

    Xinghua Lou

    2014-03-01

    Full Text Available Segmentation is a fundamental problem that dominates the success of microscopic image analysis. In almost 25 years of cell detection software development, there is still no single piece of commercial software that works well in practice when applied to early mouse embryo or stem cell image data. To address this need, we developed MINS (modular interactive nuclear segmentation as a MATLAB/C++-based segmentation tool tailored for counting cells and fluorescent intensity measurements of 2D and 3D image data. Our aim was to develop a tool that is accurate and efficient yet straightforward and user friendly. The MINS pipeline comprises three major cascaded modules: detection, segmentation, and cell position classification. An extensive evaluation of MINS on both 2D and 3D images, and comparison to related tools, reveals improvements in segmentation accuracy and usability. Thus, its accuracy and ease of use will allow MINS to be implemented for routine single-cell-level image analyses.

  15. Diagnostic Imaging for Dental Implant Therapy

    Directory of Open Access Journals (Sweden)

    Aishwarya Nagarajan

    2014-01-01

    Full Text Available Dental implant is a device made of alloplastic (foreign material implanted into the jaw bone beneath the mucosal layer to support a fixed or removable dental prosthesis. Dental implants are gaining immense popularity and wide acceptance because they not only replace lost teeth but also provide permanent restorations that do not interfere with oral function or speech or compromise the self-esteem of a patient. Appropriate treatment planning for replacement of lost teeth is required and imaging plays a pivotal role to ensure a satisfactory outcome. The development of pre-surgical imaging techniques and surgical templates helps the dentist place the implants with relative ease. This article focuses on various types of imaging modalities that have a pivotal role in implant therapy.

  16. Automatic localization of target vertebrae in spine surgery using fast CT-to-fluoroscopy (3D-2D) image registration

    Science.gov (United States)

    Otake, Y.; Schafer, S.; Stayman, J. W.; Zbijewski, W.; Kleinszig, G.; Graumann, R.; Khanna, A. J.; Siewerdsen, J. H.

    2012-02-01

    Localization of target vertebrae is an essential step in minimally invasive spine surgery, with conventional methods relying on "level counting" - i.e., manual counting of vertebrae under fluoroscopy starting from readily identifiable anatomy (e.g., the sacrum). The approach requires an undesirable level of radiation, time, and is prone to counting errors due to the similar appearance of vertebrae in projection images; wrong-level surgery occurs in 1 of every ~3000 cases. This paper proposes a method to automatically localize target vertebrae in x-ray projections using 3D-2D registration between preoperative CT (in which vertebrae are preoperatively labeled) and intraoperative fluoroscopy. The registration uses an intensity-based approach with a gradient-based similarity metric and the CMA-ES algorithm for optimization. Digitally reconstructed radiographs (DRRs) and a robust similarity metric are computed on GPU to accelerate the process. Evaluation in clinical CT data included 5,000 PA and LAT projections randomly perturbed to simulate human variability in setup of mobile intraoperative C-arm. The method demonstrated 100% success for PA view (projection error: 0.42mm) and 99.8% success for LAT view (projection error: 0.37mm). Initial implementation on GPU provided automatic target localization within about 3 sec, with further improvement underway via multi-GPU. The ability to automatically label vertebrae in fluoroscopy promises to streamline surgical workflow, improve patient safety, and reduce wrong-site surgeries, especially in large patients for whom manual methods are time consuming and error prone.

  17. Chronicle of Bukit Bunuh for possible complex impact crater by 2-D resistivity imaging (2-DERI) with geotechnical borehole records

    Science.gov (United States)

    Jinmin, M.; Saad, R.; Saidin, M.; Ismail, N. A.

    2015-03-01

    A 2-D resistivity imaging (2-DERI) study was conducted at Bukit Bunuh, Lenggong, Perak. Archaeological Global Research Centre, Universiti Sains Malaysia shows the field evidence of shock metamorphisms (suevite breccia) and crater morphology at Bukit Bunuh. A regional 2-DERI study focusing at Bukit Bunuh to identify the features of subsurface and detail study was then executed to verify boundary of the crater with the rebound effects at Bukit Bunuh which covered approximately 132.25 km2. 2-DERI survey used resistivity equipment by ABEM SAS4000 Terrameter and ES10-64C electrode slector with pole-dipole array. The survey lines were carried out using `roll-along' technique. The data were processed and analysed using RES2DINV, Excel and Surfer software to obtain resistivity results for qualitative interpretations. Bedrock depths were digitized from section by sections obtained. 2-DERI results gives both regional and detail study shows that the study area was divided into two main zones, overburden consists of alluvium mix with boulders embedded with resistivity value of 10-800 Ωm and granitic bedrock with resistivity value of >1500 Ωm and depth 5-50 m. The low level bedrock was circulated by high level bedrock (crater rim) was formed at the same area with few spots of high level bedrock which appeared at the centre of the rim which suspected as rebound zones (R). Assimilations of 2-DERI with boreholes are successful give valid and reliable results. The results of the study indicates geophysical method are capable to retrieve evidence of meteorite impact subsurface of the studied area.

  18. 2D segmentation of intervertebral discs and its degree of degeneration from T2-weighted magnetic resonance images

    Science.gov (United States)

    Castro-Mateos, Isaac; Pozo, José Maria; Lazary, Aron; Frangi, Alejandro F.

    2014-03-01

    Low back pain (LBP) is a disorder suffered by a large population around the world. A key factor causing this illness is Intervertebral Disc (IVD) degeneration, whose early diagnosis could help in preventing this widespread condition. Clinicians base their diagnosis on visual inspection of 2D slices of Magnetic Resonance (MR) images, which is subject to large interobserver variability. In this work, an automatic classification method is presented, which provides the Pfirrmann degree of degeneration from a mid-sagittal MR slice. The proposed method utilizes Active Contour Models, with a new geometrical energy, to achieve an initial segmentation, which is further improved using fuzzy C-means. Then, IVDs are classified according to their degree of degeneration. This classification is attained by employing Adaboost on five specific features: the mean and the variance of the probability map of the nucleus using two different approaches and the eccentricity of the fitting ellipse to the contour of the IVD. The classification method was evaluated using a cohort of 150 intervertebral discs assessed by three experts, resulting in a mean specificity (93%) and sensitivity (83%) similar to the one provided by every expert with respect to the most voted value. The segmentation accuracy was evaluated using the Dice Similarity Index (DSI) and Root Mean Square Error (RMSE) of the point-to-contour distance. The mean DSI ± 2 standard deviation was 91:7% ±5:6%, the mean RMSE was 0:82mm and the 95 percentile was 1:36mm. These results were found accurate when compared to the state-of-the-art.

  19. MSTAR图像2D Gabor滤波增强与自适应阈值分割%2D Gabor Filter Enhancing and Adaptive Thresholding for MSTAR Image

    Institute of Scientific and Technical Information of China (English)

    倪维平; 严卫东; 吴俊政; 芦颖; 郑刚; 马心璐

    2013-01-01

    Image segmentation is a hot point in the research field of automatic target recognition of SAR image. In order to segment the MSTAR image automatically, a new adaptive method is proposed. Firstly, 2D Gabor filters with various orientations and scales are used to enhance the original image, which can effectually reduce speckle noise in the background, and smooth the interior of the homogeneous regions. Then the analysis of the statistical characteristics of the enhanced image is made, based on which the adaptive thresholding rules is presented for the automatically segmentation of the images. Experiment results with the MSTAR images indicate that the algorithm presented has advantage of segmentation accuracy, calculation efficiency and noise robustness over the traditional methods, such as OTSU, FCM and MRF.%  为实现MSTAR图像无监督分割,并提高分割精度和计算效率,提出了一种基于Gabor滤波增强的自适应阈值分割算法。首先利用多尺度、多方向的Gabor滤波器组对待分割图像进行滤波处理,抑制目标、阴影和背景区域内部的斑噪起伏,同时增强区域间的差异性;在此基础上,通过对增强图像统计特性的分析,给出了灰度阈值计算形式,实现了MSTAR图像的自适应分割。实验结果表明,本文算法对不同斑噪强度的MSTAR图像均具有良好的处理效果,在分割精度、计算效率等方面优于传统的OTSU,以及FCM、MRF等分割方法。

  20. Plenoptic Imaging for Three-Dimensional Particle Field Diagnostics.

    Energy Technology Data Exchange (ETDEWEB)

    Guildenbecher, Daniel Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hall, Elise Munz [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-06-01

    Plenoptic imaging is a promising emerging technology for single-camera, 3D diagnostics of particle fields. In this work, recent developments towards quantitative measurements of particle size, positions, and velocities are discussed. First, the technique is proven viable with measurements of the particle field generated by the impact of a water drop on a thin film of water. Next, well cont rolled experiments are used to verify diagnostic uncertainty. Finally, an example is presented of 3D plenoptic imaging of a laboratory scale, explosively generated fragment field.

  1. Automated spectral imaging for clinical diagnostics

    Science.gov (United States)

    Breneman, John; Heffelfinger, David M.; Pettipiece, Ken; Tsai, Chris; Eden, Peter; Greene, Richard A.; Sorensen, Karen J.; Stubblebine, Will; Witney, Frank

    1998-04-01

    Bio-Rad Laboratories supplies imaging equipment for many applications in the life sciences. As part of our effort to offer more flexibility to the investigator, we are developing a microscope-based imaging spectrometer for the automated detection and analysis of either conventionally or fluorescently labeled samples. Immediate applications will include the use of fluorescence in situ hybridization (FISH) technology. The field of cytogenetics has benefited greatly from the increased sensitivity of FISH producing simplified analysis of complex chromosomal rearrangements. FISH methods for identification lends itself to automation more easily than the current cytogenetics industry standard of G- banding, however, the methods are complementary. Several technologies have been demonstrated successfully for analyzing the signals from labeled samples, including filter exchanging and interferometry. The detection system lends itself to other fluorescent applications including the display of labeled tissue sections, DNA chips, capillary electrophoresis or any other system using color as an event marker. Enhanced displays of conventionally stained specimens will also be possible.

  2. Diagnostic imaging of shoulder rotator cuff lesions

    OpenAIRE

    Nogueira-Barbosa Marcello Henrique; Volpon José Batista; Elias Jr Jorge; Muccillo Gerson

    2002-01-01

    Shoulder rotator cuff tendon tears were evaluated with ultrasonography (US) and magnetic resonance imaging (MRI). Surgical or arthroscopical correlation were available in 25 cases. Overall costs were also considered. Shoulder impingement syndrome diagnosis was done on a clinical basis. Surgery or arthroscopy was considered when conservative treatment failure for 6 months, or when rotator cuff repair was indicated. Ultrasound was performed in 22 patients and MRI in 17 of the 25 patients. Sensi...

  3. A review of diagnostic imaging of snakes and lizards.

    Science.gov (United States)

    Banzato, T; Hellebuyck, T; Van Caelenberg, A; Saunders, J H; Zotti, A

    2013-07-13

    Snakes and lizards are considered 'stoic' animals and often show only non-specific signs of illness. Consequently, diagnostic imaging--along with clinical examination and laboratory tests--is gaining importance in making a final diagnosis and establishing a correct therapy. The large number of captive snake and lizard species commonly kept as pets, together with the high inter- and intraspecific morphological variability that is innate in these animals, make the analysis of diagnostic images challenging for the veterinary practitioner. Moreover, a thorough knowledge of the anatomy, physiology and pathology of the species that are the object of clinical investigation is mandatory for the correct interpretation of diagnostic images. Despite the large amount of clinical and scientific work carried out in the past two decades, the radiographic features of snakes and lizards have not undergone systematic description, and therefore veterinarians often have to rely mostly on anatomical studies rather than radiological literature. The aim of this paper is to review the most commonly used diagnostic imaging modalities, as well as to provide an overview of the available international original studies and scientific reviews describing the normal and pathological imaging features in snakes and lizards.

  4. Correlating 2D histological slice with 3D MRI image volume using smart phone as an interactive tool for muscle study.

    Science.gov (United States)

    Eresen, Aydin; Li, Peng; Ji, Jim Xiuquan

    2014-01-01

    In muscle dystrophy studies, registration of histological image with MRI image volume enables cross validation of MRI biomarkers using pathological result. However, correlation of 2D histology slice with 3D MRI volume is technically challenging due to the potentially non-orthogonal slice plane and incomplete or distorted histological slice. This paper presents an efficient method to directly perform the 2D-3D registration. The method is unique in that it uses smart phone as a navigation tool for initial alignment followed by an overlap invariant mutual information-based refinement. Experimental results using animal muscle samples images from a 3T MRI and HE stained histological images show that the proposed method is capable of aligning the histological slice with an oblique slice in MR volume.

  5. Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect

    Energy Technology Data Exchange (ETDEWEB)

    Frary, R.; Louie, J. [UNR; Pullammanappallil, S. [Optim; Eisses, A.

    2016-08-01

    Roxanna Frary, John N. Louie, Sathish Pullammanappallil, Amy Eisses, 2011, Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract T13G-07.

  6. Non-invasive diagnostic imaging of colorectal liver metastases

    Institute of Scientific and Technical Information of China (English)

    Pier; Paolo; Mainenti; Federica; Romano; Laura; Pizzuti; Sabrina; Segreto; Giovanni; Storto; Lorenzo; Mannelli; Massimo; Imbriaco; Luigi; Camera; Simone; Maurea

    2015-01-01

    Colorectal cancer is one of the few malignant tumors in which synchronous or metachronous liver metastases [colorectal liver metastases(CRLMs)] may be treated with surgery. It has been demonstrated that resection of CRLMs improves the long-term prognosis. On the other hand, patients with un-resectable CRLMs may benefit from chemotherapy alone or in addition to liverdirected therapies. The choice of the most appropriate therapeutic management of CRLMs depends mostly on the diagnostic imaging. Nowadays, multiple non-invasive imaging modalities are available and those have a pivotal role in the workup of patients with CRLMs. Although extensive research has been performed with regards to the diagnostic performance of ultrasonography, computed tomography, positron emission tomography and magnetic resonance for the detection of CRLMs, the optimal imaging strategies for staging and follow up are still to be established. This largely due to the progressive technological and pharmacological advances which are constantly improving the accuracy of each imaging modality. This review describes the non-invasive imaging approaches of CRLMs reporting the technical features, the clinical indications, the advantages and the potential limitations of each modality, as well as including some information on the development of new imaging modalities, the role of new contrast media and the feasibility of using parametric image analysis as diagnostic marker of presence of CRLMs.

  7. Non-invasive diagnostic imaging of colorectal liver metastases.

    Science.gov (United States)

    Mainenti, Pier Paolo; Romano, Federica; Pizzuti, Laura; Segreto, Sabrina; Storto, Giovanni; Mannelli, Lorenzo; Imbriaco, Massimo; Camera, Luigi; Maurea, Simone

    2015-07-28

    Colorectal cancer is one of the few malignant tumors in which synchronous or metachronous liver metastases [colorectal liver metastases (CRLMs)] may be treated with surgery. It has been demonstrated that resection of CRLMs improves the long-term prognosis. On the other hand, patients with un-resectable CRLMs may benefit from chemotherapy alone or in addition to liver-directed therapies. The choice of the most appropriate therapeutic management of CRLMs depends mostly on the diagnostic imaging. Nowadays, multiple non-invasive imaging modalities are available and those have a pivotal role in the workup of patients with CRLMs. Although extensive research has been performed with regards to the diagnostic performance of ultrasonography, computed tomography, positron emission tomography and magnetic resonance for the detection of CRLMs, the optimal imaging strategies for staging and follow up are still to be established. This largely due to the progressive technological and pharmacological advances which are constantly improving the accuracy of each imaging modality. This review describes the non-invasive imaging approaches of CRLMs reporting the technical features, the clinical indications, the advantages and the potential limitations of each modality, as well as including some information on the development of new imaging modalities, the role of new contrast media and the feasibility of using parametric image analysis as diagnostic marker of presence of CRLMs.

  8. DIAGNOSTIC IMAGING OF THE THROWING ATHLETE’S SHOULDER

    Science.gov (United States)

    Hazle, Charles

    2013-01-01

    The diagnostic capabilities of advanced imaging have increasingly enabled clinicians to delineate between structural alterations and injuries more efficiently than ever before. These impressive gains have unfortunately begun to provide a reliance on imaging at the loss of quality in the clinical examination. Ideally, imaging of the shoulder complex is performed to confirm the provisional diagnosis developed from the history and clinical exam rather than to create such. This clinical commentary will provide the framework for both basic and advanced uses of imaging as well as discussion of evolving modalities. Level of Evidence: 5 PMID:24175143

  9. Advances in the diagnostic imaging of pheochromocytomas

    Directory of Open Access Journals (Sweden)

    Forssell-Aronsson E

    2011-05-01

    Full Text Available Eva Forssell-Aronsson1, Emil Schüler1, Håkan Ahlman21Department of Radiation Physics, 2Department of Surgery, Lundberg Laboratory of Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, SwedenAbstract: Pheochromocytomas (PCs and paragangliomas (PGLs are routinely localized by computed tomography (CT, magnetic resonance imaging (MRI, and metaiodobenzylguanidine (MIBG scintigraphy. CT can identify tumors with high sensitivity but rather low specificity. MRI has higher sensitivity and specificity than CT and is superior to detect extra-adrenal disease. Radioiodinated MIBG scintigraphy has been used for more than 30 years and is based on MIBG uptake via the norepinephrine transporter on the cell membrane. The technique is very useful for whole-body studies in case of multiple primary tumors or metastases. Tumors with sole production of dopamine usually cannot be visualized with MIBG and may require positron emission tomographic (PET studies with 18F-labeled radiotracers. Somatostatin receptor scintigraphy (SRS using the radiolabeled somatostatin analog octreotide (based on the expression of the somatostatin receptors 2 and 5 by the tumor can demonstrate PGL or metastases not visualized by MIBG. In this article, we review the use of MIBG scintigraphy to diagnose PC/PGL and compare the sensitivity and specificity with that of CT and MRI. We also describe the recent SRS and PET techniques and review the latest results of clinical studies by comparing these imaging modalities. Future perspectives of functional imaging modalities for PC/PGL are finally presented.Keywords: MIBG, scintigraphy, pheochromocytoma, paraganglioma, PET

  10. 76 FR 77834 - Scientific Information Request on Intravascular Diagnostic and Imaging Medical Devices

    Science.gov (United States)

    2011-12-14

    ... Intravascular Diagnostic and Imaging Medical Devices AGENCY: Agency for Healthcare Research and Quality (AHRQ... intravascular diagnostic and imaging medical devices, including: Fractional Flow Reserve (FFR), Coronary Flow... Resonance Imaging (MRI), Elastrography, and Thermography. Scientific information is being solicited to...

  11. Diagnostic imaging of acute pulmonary embolism.

    Science.gov (United States)

    Christiansen, F

    1997-01-01

    The common strategy of combining clinical information, lung scintigraphy and pulmonary angiography in the diagnosis of acute pulmonary embolism (PE), has many limitations in clinical use. The major causes are that pulmonary angiography and lung scintigraphy are not universally available, and that pulmonary angiography is very expensive. The purpose of this thesis was to analyse different aspects of validity in regard to lung scintigraphy, pulmonary angiography, spiral CT, and ultrasound of the legs, with the subsequent intention of discussing new diagnostic strategies. Observer variations in lung scintigraphy interpretation when applying the PIOPED criteria were tested in 2 studies with 2 and 3 observers respectively and expressed as kappa values. The ability to improve agreement in lung scintigraphy interpretation was tested by training 2 observers from different hospitals. The impact of 3 observers' variations in lung scintigraphy interpretation when compared to pulmonary angiography, was tested by comparing the ROC areas of the observers. The value of combining subjectively derived numerical probabilities and the PIOPED categorical probabilities in lung scintigraphy reporting was compared to using the PIOPED categorization only, and this was tested by comparing ROC areas. The sensitivity and specificity of detecting an embolic source in the deep veins of the legs by ultrasound as a sign of PE when lung scintigraphy is inconclusive, was tested by comparison with pulmonary angiography. The sensitivity and specificity of spiral CT, compared to pulmonary angiography, was tested by comparison to pulmonary angiography. The inter- and intra-observer kappa values were in the range of moderate and fair. It was not possible to achieve better kappa values after training. Although observer variations were substantial, the accuracy did not differ significantly between the 3 observers. Incoorporating subjectively derived probabilities into lung scan reporting could not reduce

  12. Diagnostic value of imaging in infective endocarditis: a systematic review.

    Science.gov (United States)

    Gomes, Anna; Glaudemans, Andor W J M; Touw, Daan J; van Melle, Joost P; Willems, Tineke P; Maass, Alexander H; Natour, Ehsan; Prakken, Niek H J; Borra, Ronald J H; van Geel, Peter Paul; Slart, Riemer H J A; van Assen, Sander; Sinha, Bhanu

    2017-01-01

    Sensitivity and specificity of the modified Duke criteria for native valve endocarditis are both suboptimal, at approximately 80%. Diagnostic accuracy for intracardiac prosthetic material-related infection is even lower. Non-invasive imaging modalities could potentially improve diagnosis of infective endocarditis; however, their diagnostic value is unclear. We did a systematic literature review to critically appraise the evidence for the diagnostic performance of these imaging modalities, according to PRISMA and GRADE criteria. We searched PubMed, Embase, and Cochrane databases. 31 studies were included that presented original data on the performance of electrocardiogram (ECG)-gated multidetector CT angiography (MDCTA), ECG-gated MRI, (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT, and leucocyte scintigraphy in diagnosis of native valve endocarditis, intracardiac prosthetic material-related infection, and extracardiac foci in adults. We consistently found positive albeit weak evidence for the diagnostic benefit of (18)F-FDG PET/CT and MDCTA. We conclude that additional imaging techniques should be considered if infective endocarditis is suspected. We propose an evidence-based diagnostic work-up for infective endocarditis including these non-invasive techniques. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Development of local oscillator integrated antenna array for microwave imaging diagnostics

    Science.gov (United States)

    Kuwahara, D.; Ito, N.; Nagayama, Y.; Tsuchiya, H.; Yoshikawa, M.; Kohagura, J.; Yoshinaga, T.; Yamaguchi, S.; Kogi, Y.; Mase, A.; Shinohara, S.

    2015-12-01

    Microwave imaging diagnostics are powerful tools that are used to obtain details of complex structures and behaviors of such systems as magnetically confined plasmas. For example, microwave imaging reflectometry and microwave imaging interferometers are suitable for observing phenomena that are involved with electron density fluctuations; moreover, electron cyclotron emission imaging diagnostics enable us to accomplish the significant task of observing MHD instabilities in large tokamaks. However, microwave imaging systems include difficulties in terms of multi-channelization and cost. Recently, we solved these problems by developing a Horn-antenna Mixer Array (HMA), a 50 - 110 GHz 1-D heterodyne- type antenna array, which can be easily stacked as a 2-D receiving array, because it uses an end-fire element. However, the HMA still evidenced problems owing to the requirement for local oscillation (LO) optics and an expensive high-power LO source. To solve this problem, we have developed an upgraded HMA, named the Local Integrated Antenna array (LIA), in which each channel has an internal LO supply using a frequency multiplier integrated circuit. Therefore, the proposed antenna array eliminates the need for both the LO optics and the high-power LO source. This paper describes the principle of the LIA, and provides details about an 8 channel prototype LIA.

  14. Imagens em 2D e 3D geradas pela TC Cone-Beam e radiografias convencionais: qual a mais confiável? 2D / 3D Cone-Beam CT images or conventional radiography: which is more reliable?

    Directory of Open Access Journals (Sweden)

    Carolina Perez Couceiro

    2010-10-01

    Full Text Available OBJETIVO: comparar a confiabilidade de identificação dos pontos visualizados sobre radiografias cefalométricas convencionais e sobre imagens geradas pela Tomografia Computadorizada Cone-Beam em 2D e 3D. MÉTODOS: o material constou de imagens obtidas através do tomógrafo computadorizado Cone-Beam, em norma lateral, em 2D e 3D, impressas em papel fotográfico; e radiografias cefalométricas laterais, realizadas na mesma clínica radiológica e no mesmo dia, de dois pacientes pertencentes aos arquivos do Curso de Especialização em Ortodontia da Faculdade de Odontologia da Universidade Federal Fluminense (UFF. Dez alunos do Curso de Especialização em Ortodontia da UFF identificaram pontos de referência sobre papel de acetato transparente e foram feitas medições das seguintes variáveis cefalométricas: ANB, FMIA, IMPA, FMA, ângulo interincisal, 1-NA (mm e ¯1-NB (mm. Em seguida, foram calculadas médias aritméticas, desvios-padrão e coeficientes de variância de cada variável para os dois pacientes. RESULTADOS E CONCLUSÃO: os valores das medições realizadas a partir de imagens em 3D apresentaram menor dispersão, sugerindo que essas imagens são mais confiáveis quanto à identificação de alguns pontos cefalométricos. Entretanto, como as imagens em 3D impressas utilizadas no presente estudo não permitiram a visualização de pontos intracranianos, torna-se necessário que softwares específicos sejam elaborados para que esse tipo de exame possa se tornar rotineiro na clínica ortodôntica.OBJECTIVE: To compare the reliability of two different methods used for viewing and identifying cephalometric landmarks, i.e., (a using conventional cephalometric radiographs, and (b using 2D and 3D images generated by Cone-Beam Computed Tomography. METHODS: The material consisted of lateral view 2D and 3D images obtained by Cone-Beam Computed Tomography printed on photo paper, and lateral cephalometric radiographs, taken in the same

  15. Cerebrovascular diagnostics - Imaging; Zerebrale Gefaessdiagnostik - Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Roth, C. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg (Germany)

    2012-12-15

    Imaging of the cerebral vasculature relies mostly on computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA). Although DSA is still the gold standard, many questions can be answered with CTA and/or MRA thanks to recent technological advances. The following article describes the advantages and disadvantages of these techniques with regard to different questions. Basic principles regarding the different techniques are explained. (orig.) [German] Die Bildgebung der zerebralen Gefaesse stuetzt sich im Wesentlichen auf die CT-Angiographie (CTA), MR-Angiographie (MRA) und die digitale Subtraktionsangiographie (DSA). Obwohl die DSA nach wie vor als Goldstandard gilt, lassen sich durch die technischen Neuerungen der Schnittbilddiagnostik viele Fragestellungen mithilfe von CTA und MR-A beantworten. Im nachfolgenden Artikel werden im Hinblick auf verschiedene Fragestellungen Vor- und Nachteile der einzelnen Verfahren aufgefuehrt sowie Grundlagen zu den einzelnen Techniken erlaeutert. (orig.)

  16. Intraoperative evaluation of device placement in spine surgery using known-component 3D-2D image registration.

    Science.gov (United States)

    Uneri, A; De Silva, T; Goerres, J; Jacobson, M W; Ketcha, M D; Reaungamornrat, S; Kleinszig, G; Vogt, S; Khanna, A J; Osgood, G M; Wolinsky, J-P; Siewerdsen, J H

    2017-04-21

    Intraoperative x-ray radiography/fluoroscopy is commonly used to assess the placement of surgical devices in the operating room (e.g. spine pedicle screws), but qualitative interpretation can fail to reliably detect suboptimal delivery and/or breach of adjacent critical structures. We present a 3D-2D image registration method wherein intraoperative radiographs are leveraged in combination with prior knowledge of the patient and surgical components for quantitative assessment of device placement and more rigorous quality assurance (QA) of the surgical product. The algorithm is based on known-component registration (KC-Reg) in which patient-specific preoperative CT and parametric component models are used. The registration performs optimization of gradient similarity, removes the need for offline geometric calibration of the C-arm, and simultaneously solves for multiple component bodies, thereby allowing QA in a single step (e.g. spinal construct with 4-20 screws). Performance was tested in a spine phantom, and first clinical results are reported for QA of transpedicle screws delivered in a patient undergoing thoracolumbar spine surgery. Simultaneous registration of ten pedicle screws (five contralateral pairs) demonstrated mean target registration error (TRE) of 1.1  ±  0.1 mm at the screw tip and 0.7  ±  0.4° in angulation when a prior geometric calibration was used. The calibration-free formulation, with the aid of component collision constraints, achieved TRE of 1.4  ±  0.6 mm. In all cases, a statistically significant improvement (p  <  0.05) was observed for the simultaneous solutions in comparison to previously reported sequential solution of individual components. Initial application in clinical data in spine surgery demonstrated TRE of 2.7  ±  2.6 mm and 1.5  ±  0.8°. The KC-Reg algorithm offers an independent check and quantitative QA of the surgical product using radiographic/fluoroscopic views

  17. Diagnostic imaging of craniofacial trauma and fractures and their sequelae; Bildgebende Diagnostik bei Gesichtsschaedelfrakturen und Traumafolgen

    Energy Technology Data Exchange (ETDEWEB)

    Buitrago-Tellez, C.H. [Kantonspital Basel (Switzerland). Universitaetsinstitut fuer Radiologie; Kunz, C. [Kantonspital Basel (Switzerland). Abt. Kiefer- und Gesichtschirurgie

    2001-12-01

    The value and applications of the CT modalities are on the rise, particularly since the availability of spiral CT techniques, while conventional native diagnostics is increasingly used for special imaging purposes. Multiplanar spiral CT enables high-quality coronary 2D reconstructions which, in the acute phase, make redundant primary coronary imaging modalities. Exact knowledge of typical fracture patterns facilitates the analysis of images of the relevant facial areas. 3D reconstructions are indispensable in pin-pointed surgery planning, generation of stereolithographic models, and image-guided interventions for examination of post-traumatic deformities. Since a secondary correction only very rarely leads to restitutio ad integrum, it is necessary to detect the therapy-relevant injuries very early, during acute diagnostic imaging, in order to lay the basis for subsequent therapy and restoration of the craniofacial structures and functions. (orig./CB) [German] Waehrend die konventionelle Nativdiagnostik sich zunehmend auf wenige Spezialaufnahmen (NNH, OPT) beschraenkt, nimmt die Bedeutung der CT insbesondere seit Einfuehrung der Spiral-CT-Technik deutlich zu. Durch die Mehrschicht-Spiral-CT sind hochwertige koronare 2D-Rekonstruktionen moeglich, die in der Akutphase eine primaere koronare Schnittfuehrung entbehrlich erscheinen lassen. Die genaue Kenntnis typischer Frakturmuster erleichtert die Bildanalyse der relevanten Gesichtsregionen. Waehrend 3D-Rekonstruktionen in der Akutphase selten von diagnostischer Bedeutung sind, werden sie zur genauen praeoperativen Planung, Anfertigung stereolithographischer Modelle sowie navigationsbasierten Interventionen bei der Abklaerung posttraumatischer Deformitaeten eingesetzt. Da eine sekundaere Korrektur selten zur Restitutio ad integrum fuehrt, ist es notwendig, die therapierelevanten Verletzungen in der Akutdiagnostik - rechtzeitig - zu erkennen, um eine fachgerechte Behandlung zu ermoeglichen und dadurch die

  18. Diagnostic imaging advances in murine models of colitis.

    Science.gov (United States)

    Brückner, Markus; Lenz, Philipp; Mücke, Marcus M; Gohar, Faekah; Willeke, Peter; Domagk, Dirk; Bettenworth, Dominik

    2016-01-21

    Inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis are chronic-remittent inflammatory disorders of the gastrointestinal tract still evoking challenging clinical diagnostic and therapeutic situations. Murine models of experimental colitis are a vital component of research into human IBD concerning questions of its complex pathogenesis or the evaluation of potential new drugs. To monitor the course of colitis, to the present day, classical parameters like histological tissue alterations or analysis of mucosal cytokine/chemokine expression often require euthanasia of animals. Recent advances mean revolutionary non-invasive imaging techniques for in vivo murine colitis diagnostics are increasingly available. These novel and emerging imaging techniques not only allow direct visualization of intestinal inflammation, but also enable molecular imaging and targeting of specific alterations of the inflamed murine mucosa. For the first time, in vivo imaging techniques allow for longitudinal examinations and evaluation of intra-individual therapeutic response. This review discusses the latest developments in the different fields of ultrasound, molecularly targeted contrast agent ultrasound, fluorescence endoscopy, confocal laser endomicroscopy as well as tomographic imaging with magnetic resonance imaging, computed tomography and fluorescence-mediated tomography, discussing their individual limitations and potential future diagnostic applications in the management of human patients with IBD.

  19. Diagnostic Medical Imaging in Pediatric Patients and Subsequent Cancer Risk.

    Science.gov (United States)

    Mulvihill, David J; Jhawar, Sachin; Kostis, John B; Goyal, Sharad

    2017-06-20

    The use of diagnostic medical imaging is becoming increasingly more commonplace in the pediatric setting. However, many medical imaging modalities expose pediatric patients to ionizing radiation, which has been shown to increase the risk of cancer development in later life. This review article provides a comprehensive overview of the available data regarding the risk of cancer development following exposure to ionizing radiation from diagnostic medical imaging. Attention is paid to modalities such as computed tomography scans and fluoroscopic procedures that can expose children to radiation doses orders of magnitude higher than standard diagnostic x-rays. Ongoing studies that seek to more precisely determine the relationship of diagnostic medical radiation in children and subsequent cancer development are discussed, as well as modern strategies to better quantify this risk. Finally, as cardiovascular imaging and intervention contribute substantially to medical radiation exposure, we discuss strategies to enhance radiation safety in these areas. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  20. Early diagnostic method for sepsis based on neutrophil MR imaging

    Directory of Open Access Journals (Sweden)

    Shanhua Han

    2015-06-01

    Conclusion: Mouse and human neutrophils could be more effectively labelled by Mannan-coated SPION in vitro than Feridex. Sepsis analog neutrophils labelled by Mannan-coated SPIONs could be efficiently detected on MR images, which may serve as an early diagnostic method for sepsis.

  1. Phyllodes tumor: diagnostic imaging and histopathology findings.

    Science.gov (United States)

    Venter, Alina Cristiana; Roşca, Elena; Daina, Lucia Georgeta; Muţiu, Gabriela; Pirte, Adriana Nicoleta; Rahotă, Daniela

    2015-01-01

    Phyllodes tumors are rare breast tumors, accounting for less than 1% of all primary tumors of the breast. Histologically, phyllodes tumors can be divided into benign (60%), borderline (20%) and malignant (20%). The mammography examination was performed by means of a digital mammography system Giotto 3D Images; the ultrasound examination was performed through a GE Logiq P6 device and histological confirmation was possible after surgery or following the histological biopsy. We grouped the nine patients who presented clinically palpable nodules into two groups, namely: the six patients presenting histological benign results into Group I, and Group II where we included those with borderline and malignant histological results. Mammography performed in 77.7% revealed a well-circumscribed round or oval opacity or with contour lobules. Ultrasound examination was performed in all patients. Mammography and ultrasound have limitation in differentiating between benign lesion and phyllodes tumor. In the nine analyzed cases, mammographic and ultrasound examinations did not allow the differentiation into the three groups of phyllodes tumor. Histopathological examination is considered the golden standard for their diagnosis. Correlations between mammographic and microscopic aspects were inconclusive for determining the degree of differentiation, ultrasound changes could be correlated with the histopathological aspects.

  2. Diagnostic imaging of shoulder rotator cuff lesions

    Directory of Open Access Journals (Sweden)

    Nogueira-Barbosa Marcello Henrique

    2002-01-01

    Full Text Available Shoulder rotator cuff tendon tears were evaluated with ultrasonography (US and magnetic resonance imaging (MRI. Surgical or arthroscopical correlation were available in 25 cases. Overall costs were also considered. Shoulder impingement syndrome diagnosis was done on a clinical basis. Surgery or arthroscopy was considered when conservative treatment failure for 6 months, or when rotator cuff repair was indicated. Ultrasound was performed in 22 patients and MRI in 17 of the 25 patients. Sensitivity, specificity and accuracy were 80%, 100% and 90.9% for US and 90%, 100% and 94.12% for MRI, respectively. In 16 cases both US and MRI were obtained and in this subgroup statistical correlation was excellent (p< 0.001. We concluded that both methods are reliable for rotator cuff full thickness tear evaluation. Since US is less expensive, it could be considered as the screening method when rotator cuff integrity is the main question, and when well trained radiologists and high resolution equipment are available.

  3. 3D ultrasound imaging for prosthesis fabrication and diagnostic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Morimoto, A.K.; Bow, W.J.; Strong, D.S. [and others

    1995-06-01

    The fabrication of a prosthetic socket for a below-the-knee amputee requires knowledge of the underlying bone structure in order to provide pressure relief for sensitive areas and support for load bearing areas. The goal is to enable the residual limb to bear pressure with greater ease and utility. Conventional methods of prosthesis fabrication are based on limited knowledge about the patient`s underlying bone structure. A 3D ultrasound imaging system was developed at Sandia National Laboratories. The imaging system provides information about the location of the bones in the residual limb along with the shape of the skin surface. Computer assisted design (CAD) software can use this data to design prosthetic sockets for amputees. Ultrasound was selected as the imaging modality. A computer model was developed to analyze the effect of the various scanning parameters and to assist in the design of the overall system. The 3D ultrasound imaging system combines off-the-shelf technology for image capturing, custom hardware, and control and image processing software to generate two types of image data -- volumetric and planar. Both volumetric and planar images reveal definition of skin and bone geometry with planar images providing details on muscle fascial planes, muscle/fat interfaces, and blood vessel definition. The 3D ultrasound imaging system was tested on 9 unilateral below-the- knee amputees. Image data was acquired from both the sound limb and the residual limb. The imaging system was operated in both volumetric and planar formats. An x-ray CT (Computed Tomography) scan was performed on each amputee for comparison. Results of the test indicate beneficial use of ultrasound to generate databases for fabrication of prostheses at a lower cost and with better initial fit as compared to manually fabricated prostheses.

  4. Autofluorescence-based diagnostic UV imaging of tissues and cells

    Science.gov (United States)

    Renkoski, Timothy E.

    Cancer is the second leading cause of death in the United States, and its early diagnosis is critical to improving treatment options and patient outcomes. In autofluorescence (AF) imaging, light of controlled wavelengths is projected onto tissue, absorbed by specific molecules, and re-emitted at longer wavelengths. Images of re-emitted light are used together with spectral information to infer tissue functional information and diagnosis. This dissertation describes AF imaging studies of three different organs using data collected from fresh human surgical specimens. In the ovary study, illumination was at 365 nm, and images were captured at 8 emission wavelengths. Measurements from a multispectral imaging system and fiber optic probe were used to map tissue diagnosis at every image pixel. For the colon and pancreas studies, instrumentation was developed extending AF imaging capability to sub-300 nm excitation. Images excited in the deep UV revealed tryptophan and protein content which are believed to change with disease state. Several excitation wavelength bands from 280 nm to 440 nm were investigated. Microscopic AF images collected in the pancreas study included both cultured and primary cells. Several findings are reported. A method of transforming fiber optic probe spectra for direct comparison with imager spectra was devised. Normalization of AF data by green reflectance data was found useful in correcting hemoglobin absorption. Ratio images, both AF and reflectance, were formulated to highlight growths in the colon. Novel tryptophan AF images were found less useful for colon diagnostics than the new ratio techniques. Microscopic tryptophan AF images produce useful visualization of cellular protein content, but their diagnostic value requires further study.

  5. Comparison of 3D double inversion recovery and 2D STIR FLAIR MR sequences for the imaging of optic neuritis: pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Hodel, Jerome; Bocher, Anne-Laure; Pruvo, Jean-Pierre; Leclerc, Xavier [Hopital Roger Salengro, Department of Neuroradiology, Lille (France); Outteryck, Olivier; Zephir, Helene; Vermersch, Patrick [Hopital Roger Salengro, Department of Neurology, Lille (France); Lambert, Oriane [Fondation Ophtalmologique Rothschild, Department of Neuroradiology, Paris (France); Benadjaoud, Mohamed Amine [Radiation Epidemiology Team, Inserm, CESP Centre for Research in Epidemiology and Population Health, U1018, Villejuif (France); Chechin, David [Philips Medical Systems, Suresnes (France)

    2014-12-15

    We compared the three-dimensional (3D) double inversion recovery (DIR) magnetic resonance imaging (MRI) sequence with the coronal two-dimensional (2D) short tau inversion recovery (STIR) fluid-attenuated inversion recovery (FLAIR) for the detection of optic nerve signal abnormality in patients with optic neuritis (ON). The study group consisted of 31 patients with ON (44 pathological nerves) confirmed by visual-evoked potentials used as the reference. MRI examinations included 2D coronal STIR FLAIR and 3D DIR with 3-mm coronal reformats to match with STIR FLAIR. Image artefacts were graded for each portion of the optic nerves. Each set of MR images (2D STIR FLAIR, DIR reformats and multiplanar 3D DIR) was examined independently and separately for the detection of signal abnormality. Cisternal portion of optic nerves was better delineated with DIR (p < 0.001), while artefacts impaired analysis in four patients with STIR FLAIR. Inter-observer agreement was significantly improved (p < 0.001) on 3D DIR (κ = 0.96) compared with STIR FLAIR images (κ = 0.60). Multiplanar DIR images reached the best performance for the diagnosis of ON (95 % sensitive and 94 % specific). Our study showed a high sensitivity and specificity of 3D DIR compared with STIR FLAIR for the detection of ON. These findings suggest that the 3D DIR sequence may be more useful in patients suspected of ON. (orig.)

  6. MTF characterization in 2D and 3D for a high resolution, large field of view flat panel imager for cone beam CT

    Science.gov (United States)

    Shah, Jainil; Mann, Steve D.; Tornai, Martin P.; Richmond, Michelle; Zentai, George

    2014-03-01

    The 2D and 3D modulation transfer functions (MTFs) of a custom made, large 40x30cm2 area, 600- micron CsI-TFT based flat panel imager having 127-micron pixellation, along with the micro-fiber scintillator structure, were characterized in detail using various techniques. The larger area detector yields a reconstructed FOV of 25cm diameter with an 80cm SID in CT mode. The MTFs were determined with 1x1 (intrinsic) binning. The 2D MTFs were determined using a 50.8 micron tungsten wire and a solid lead edge, and the 3D MTF was measured using a custom made phantom consisting of three nearly orthogonal 50.8 micron tungsten wires suspended in an acrylic cubic frame. The 2D projection data was reconstructed using an iterative OSC algorithm using 16 subsets and 5 iterations. As additional verification of the resolution, along with scatter, the Catphan® phantom was also imaged and reconstructed with identical parameters. The measured 2D MTF was ~4% using the wire technique and ~1% using the edge technique at the 3.94 lp/mm Nyquist cut-off frequency. The average 3D MTF measured along the wires was ~8% at the Nyquist. At 50% MTF, the resolutions were 1.2 and 2.1 lp/mm in 2D and 3D, respectively. In the Catphan® phantom, the 1.7 lp/mm bars were easily observed. Lastly, the 3D MTF measured on the three wires has an observed 5.9% RMSD, indicating that the resolution of the imaging system is uniform and spatially independent. This high performance detector is integrated into a dedicated breast SPECT-CT imaging system.

  7. Assessment of Prosthesis Alignment after Revision Total Knee Arthroplasty Using EOS 2D and 3D Imaging : A Reliability Study

    NARCIS (Netherlands)

    Meijer, Marrigje F.; Boerboom, Alexander L.; Stevens, Martin; Bulstra, Sjoerd K.; Reininga, Inge H. F.

    2014-01-01

    Introduction: A new low-dose X-ray device, called EOS, has been introduced for determining lower-limb alignment in 2D and 3D. Reliability has not yet been assessed when using EOS on lower limbs containing a knee prosthesis. Therefore purpose of this study was to determine intraobserver and interobse

  8. Diagnostic imaging in psychiatry; Bildgebende Verfahren in der Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Stoppe, G.; Hentschel, F.; Munz, D.L. (eds.)

    2000-07-01

    The textbook presents an exhaustive survey of diagnostic imaging methods available for clinical evaluation of the entire range of significant psychiatric symptoms via imaging of the anatomy and functions of the brain. The chapters discuss: The methods and their efficient use for given diagnostic objectives, image analysis, description and interpretation of findings with respect to the clinical symptoms. Morphology and functional correlation of findings. The book is intended to help psychiatrists and neurologists as well as doctors in the radiology and nuclear medicine departments. (orig./CB) [German] Die Entwicklung der modernen Bildgebung ermoeglicht faszinierende Einblicke in Anatomie und Funktionen des Gehirns und ihre Veraenderungen bei psychiatrischen Erkrankungen. Die Methodik der Untersuchungsverfahren und die Befunde bei allen wichtigen psychiatrischen Krankheitsbildern sind in diesem Buch systematisch und umfassend beschrieben: - gezielter und effizienter Einsatz der Verfahren, - Bildanalyse und Befundbeschreibung, - Bewertung der Befunde und Beziehung zum klinischen Bild, - morphologische und funktionelle Korrelate der Befunde. Psychiater und Neurologen werden ebenso angesprochen wie Radiologen und Nuklearmediziner. (orig.)

  9. First Results from a Coherence Imaging Diagnostic for the Compact Toroidal Hybrid

    Science.gov (United States)

    Ennis, D. A.; Hartwell, G. J.; Johnson, C. A.; Maurer, D. A.; Allen, S. L.

    2015-11-01

    An optical coherence imaging diagnostic is being commissioned for time-resolved measurements (~ 10 ms) of ion emissivity, velocity, and temperature in the Compact Toroidal Hybrid (CTH) experiment. The Coherence Imaging (CI) technique measures the spectral coherence of an emission line with an imaging interferometer of fixed delay. CI has a number of advantages when compared to dispersive Doppler spectroscopy, including higher throughput and the capability to provide 2D spectral images, making it advantageous for investigating the non-axisymmetric geometry of CTH plasmas. A spectral survey of the visible and ultraviolet emission for a range of CTH discharges has identified helium and carbon impurity lines that will be utilized for CI measurements in CTH. First CI measurements of He II (468.6 nm) emission from CTH plasmas will be presented along with interferograms from a calibration light source and details of the instrument design. Results from this diagnostic will aid in characterizing the equilibrium ion parameters in both the edge and core of CTH plasmas for planned island divertor and MHD mode-locking experiments. Work supported by USDoE grant DE-FG02-00ER54610.

  10. Textural analyses of carbon fiber materials by 2D-FFT of complex images obtained by high frequency eddy current imaging (HF-ECI)

    Science.gov (United States)

    Schulze, Martin H.; Heuer, Henning

    2012-04-01

    Carbon fiber based materials are used in many lightweight applications in aeronautical, automotive, machine and civil engineering application. By the increasing automation in the production process of CFRP laminates a manual optical inspection of each resin transfer molding (RTM) layer is not practicable. Due to the limitation to surface inspection, the quality parameters of multilayer 3 dimensional materials cannot be observed by optical systems. The Imaging Eddy- Current (EC) NDT is the only suitable inspection method for non-resin materials in the textile state that allows an inspection of surface and hidden layers in parallel. The HF-ECI method has the capability to measure layer displacements (misaligned angle orientations) and gap sizes in a multilayer carbon fiber structure. EC technique uses the variation of the electrical conductivity of carbon based materials to obtain material properties. Beside the determination of textural parameters like layer orientation and gap sizes between rovings, the detection of foreign polymer particles, fuzzy balls or visualization of undulations can be done by the method. For all of these typical parameters an imaging classification process chain based on a high resolving directional ECimaging device named EddyCus® MPECS and a 2D-FFT with adapted preprocessing algorithms are developed.

  11. Image standards in Tissue-Based Diagnosis (Diagnostic Surgical Pathology

    Directory of Open Access Journals (Sweden)

    Vollmer Ekkehard

    2008-04-01

    Full Text Available Abstract Background Progress in automated image analysis, virtual microscopy, hospital information systems, and interdisciplinary data exchange require image standards to be applied in tissue-based diagnosis. Aims To describe the theoretical background, practical experiences and comparable solutions in other medical fields to promote image standards applicable for diagnostic pathology. Theory and experiences Images used in tissue-based diagnosis present with pathology – specific characteristics. It seems appropriate to discuss their characteristics and potential standardization in relation to the levels of hierarchy in which they appear. All levels can be divided into legal, medical, and technological properties. Standards applied to the first level include regulations or aims to be fulfilled. In legal properties, they have to regulate features of privacy, image documentation, transmission, and presentation; in medical properties, features of disease – image combination, human – diagnostics, automated information extraction, archive retrieval and access; and in technological properties features of image acquisition, display, formats, transfer speed, safety, and system dynamics. The next lower second level has to implement the prescriptions of the upper one, i.e. describe how they are implemented. Legal aspects should demand secure encryption for privacy of all patient related data, image archives that include all images used for diagnostics for a period of 10 years at minimum, accurate annotations of dates and viewing, and precise hardware and software information. Medical aspects should demand standardized patients' files such as DICOM 3 or HL 7 including history and previous examinations, information of image display hardware and software, of image resolution and fields of view, of relation between sizes of biological objects and image sizes, and of access to archives and retrieval. Technological aspects should deal with image

  12. Image standards in tissue-based diagnosis (diagnostic surgical pathology).

    Science.gov (United States)

    Kayser, Klaus; Görtler, Jürgen; Goldmann, Torsten; Vollmer, Ekkehard; Hufnagl, Peter; Kayser, Gian

    2008-04-18

    Progress in automated image analysis, virtual microscopy, hospital information systems, and interdisciplinary data exchange require image standards to be applied in tissue-based diagnosis. To describe the theoretical background, practical experiences and comparable solutions in other medical fields to promote image standards applicable for diagnostic pathology. THEORY AND EXPERIENCES: Images used in tissue-based diagnosis present with pathology-specific characteristics. It seems appropriate to discuss their characteristics and potential standardization in relation to the levels of hierarchy in which they appear. All levels can be divided into legal, medical, and technological properties. Standards applied to the first level include regulations or aims to be fulfilled. In legal properties, they have to regulate features of privacy, image documentation, transmission, and presentation; in medical properties, features of disease-image combination, human-diagnostics, automated information extraction, archive retrieval and access; and in technological properties features of image acquisition, display, formats, transfer speed, safety, and system dynamics. The next lower second level has to implement the prescriptions of the upper one, i.e. describe how they are implemented. Legal aspects should demand secure encryption for privacy of all patient related data, image archives that include all images used for diagnostics for a period of 10 years at minimum, accurate annotations of dates and viewing, and precise hardware and software information. Medical aspects should demand standardized patients' files such as DICOM 3 or HL 7 including history and previous examinations, information of image display hardware and software, of image resolution and fields of view, of relation between sizes of biological objects and image sizes, and of access to archives and retrieval. Technological aspects should deal with image acquisition systems (resolution, colour temperature, focus

  13. Correlation and convolution filtering and image processing for pitch evaluation of 2D micro- and nano-scale gratings and lattices.

    Science.gov (United States)

    Chen, Xiaomei; Koenders, Ludger; Parkinson, Simon

    2017-03-20

    We have mathematically explicated and experimentally demonstrated how a correlation and convolution filter can dramatically suppress the noise that coexists with the scanned topographic signals of two-dimensional (2D) gratings and lattices with 2D perspectives. To realize pitch evaluation, the true peaks' coordinates have been precisely acquired after detecting the local maxima from the filtered signal, followed by image processing. The combination of 2D filtering, local-maxima detecting, and image processing make up the pitch detection (PD) method. It is elucidated that the pitch average, uniformity, rotation angle, and orthogonal angle can be calculated using the PD method. This has been applied to the pitch evaluation of several 2D gratings and lattices, and the results are compared with the results of using the center-of-gravity (CG) and Fourier-transform-based (FT) method. The differences of pitch averages which are produced using the PD, CG, and FT methods are within 1.5 pixels. Moreover, the PD method has also been applied to detect the dense peaks of Si (111) 7×7 surface and the highly oriented pyrolytic graphite (HOPG) basal plane.

  14. Computers in Diagnostic Nuclear Medicine Imaging - A Review

    Directory of Open Access Journals (Sweden)

    K. K. Kapoor

    1989-07-01

    Full Text Available Digital computers are becoming increasingly popular for a variety of purposes in nuclear medicine. They are particuiarly useful in the areas of nuclear imaging and gamma camera image processing,radionuclide inventory and patient record keeping. By far the most important use of the digital computer is in array processors which are commonly available with emission computed systems for fast reconstruction of images in transverse, coronal and sagittal views, particularly when the data to be handled is enormous and involves filtration and correction processes. The addition of array processors to computer systems has helped the clinicians in improving diagnostic nuclear medicine imaging capability. This paper reviews briefly therole of computers in the field of nuclear medicine imaging.

  15. Optimizing Patient-centered Communication and Multidisciplinary Care Coordination in Emergency Diagnostic Imaging: A Research Agenda.

    Science.gov (United States)

    Sabbatini, Amber K; Merck, Lisa H; Froemming, Adam T; Vaughan, William; Brown, Michael D; Hess, Erik P; Applegate, Kimberly E; Comfere, Nneka I

    2015-12-01

    Patient-centered emergency diagnostic imaging relies on efficient communication and multispecialty care coordination to ensure optimal imaging utilization. The construct of the emergency diagnostic imaging care coordination cycle with three main phases (pretest, test, and posttest) provides a useful framework to evaluate care coordination in patient-centered emergency diagnostic imaging. This article summarizes findings reached during the patient-centered outcomes session of the 2015 Academic Emergency Medicine consensus conference "Diagnostic Imaging in the Emergency Department: A Research Agenda to Optimize Utilization." The primary objective was to develop a research agenda focused on 1) defining component parts of the emergency diagnostic imaging care coordination process, 2) identifying gaps in communication that affect emergency diagnostic imaging, and 3) defining optimal methods of communication and multidisciplinary care coordination that ensure patient-centered emergency diagnostic imaging. Prioritized research questions provided the framework to define a research agenda for multidisciplinary care coordination in emergency diagnostic imaging.

  16. Healthcare provider and patient perspectives on diagnostic imaging investigations

    Science.gov (United States)

    Bergh, Anne-Marie; Hoffmann, Willem A.

    2015-01-01

    Background: Much has been written about the patient-centred approach in doctor–patient consultations. Little is known about interactions and communication processes regarding healthcare providers’ and patients’ perspectives on expectations and experiences of diagnostic imaging investigations within the medical encounter. Patients journey through the health system from the point of referral to the imaging investigation itself and then to the post-imaging consultation. Aim and setting: To explore healthcare provider and patient perspectives on interaction and communication processes during diagnostic imaging investigations as part of their clinical journey through a healthcare complex. Methods: A qualitative study was conducted, with two phases of data collection. Twenty-four patients were conveniently selected at a public district hospital complex and were followed throughout their journey in the hospital system, from admission to discharge. The second phase entailed focus group interviews conducted with providers in the district hospital and adjacent academic hospital (medical officers and family physicians, nurses, radiographers, radiology consultants and registrars). Results: Two main themes guided our analysis: (1) provider perspectives; and (2) patient dispositions and reactions. Golden threads that cut across these themes are interactions and communication processes in the context of expectations, experiences of the imaging investigations and the outcomes thereof. Conclusion: Insights from this study provide a better understanding of the complexity of the processes and interactions between providers and patients during the imaging investigations conducted as part of their clinical pathway. The interactions and communication processes are provider–patient centred when a referral for a diagnostic imaging investigation is included. PMID:26245604

  17. Combining a thermal-imaging diagnostic with an existing imaging VISAR diagnostic at the National Ignition Facility (NIF)

    Science.gov (United States)

    Malone, Robert M.; Celeste, John R.; Celliers, Peter M.; Frogget, Brent C.; Guyton, Robert L.; Kaufman, Morris I.; Lee, Tony L.; MacGowan, Brian J.; Ng, Edmund W.; Reinbachs, Imants P.; Robinson, Ronald B.; Seppala, Lynn G.; Tunnell, Thomas W.; Watts, Phillip W.

    2005-08-01

    Optical diagnostics are currently being designed to analyze high-energy density physics experiments at the National Ignition Facility (NIF). Two independent line-imaging Velocity Interferometer System for Any Reflector (VISAR) interferometers have been fielded to measure shock velocities, breakout times, and emission of targets having sizes of 1-5 mm. An 8-inch-diameter, fused silica triplet lens collects light at f/3 inside the 30-foot-diameter NIF vacuum chamber. VISAR recordings use a 659.5-nm probe laser. By adding a specially coated beam splitter to the interferometer table, light at wavelengths from 540 to 645 nm is spilt into a thermal-imaging diagnostic. Because fused silica lenses are used in the first triplet relay, the intermediate image planes for different wavelengths separate by considerable distances. A corrector lens on the interferometer table reunites these separated wavelength planes to provide a good image. Thermal imaging collects light at f/5 from a 2-mm object placed at Target Chamber Center (TCC). Streak cameras perform VISAR and thermal-imaging recording. All optical lenses are on kinematic mounts so that pointing accuracy of the optical axis may be checked. Counter-propagating laser beams (orange and red) are used to align both diagnostics. The red alignment laser is selected to be at the 50 percent reflection point of the beam splitter. This alignment laser is introduced at the recording streak cameras for both diagnostics and passes through this special beam splitter on its way into the NIF vacuum chamber.

  18. Combining a thermal-imaging diagnostic with an existing imaging VISAR diagnostic at the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Malone; John R. Celesteb; Peter M. Celliers; Brent C. Froggeta; Robert L. Guyton; Morris I. Kaufman; Tony L. Lee; Brian J. MacGowan; Edmund W. Ng; Imants P. Reinbachs; Ronald B. Robinson; Lynn G. Seppala; Tom W. Tunnell; Phillip W. Watts

    2005-01-01

    Optical diagnostics are currently being designed to analyze high-energy density physics experiments at the National Ignition Facility (NIF). Two independent line-imaging Velocity Interferometer System for Any Reflector (VISAR) interferometers have been fielded to measure shock velocities, breakout times, and emission of targets having sizes of 1–5 mm. An 8-inch-diameter, fused silica triplet lens collects light at f/3 inside the 30-foot-diameter NIF vacuum chamber. VISAR recordings use a 659.5-nm probe laser. By adding a specially coated beam splitter to the interferometer table, light at wavelengths from 540 to 645 nm is spilt into a thermal-imaging diagnostic. Because fused silica lenses are used in the first triplet relay, the intermediate image planes for different wavelengths separate by considerable distances. A corrector lens on the interferometer table reunites these separated wavelength planes to provide a good image. Thermal imaging collects light at f/5 from a 2-mm object placed at Target Chamber Center (TCC). Streak cameras perform VISAR and thermal-imaging recording. All optical lenses are on kinematic mounts so that pointing accuracy of the optical axis may be checked. Counter-propagating laser beams (orange and red) are used to align both diagnostics. The red alignment laser is selected to be at the 50 percent reflection point of the beam splitter. This alignment laser is introduced at the recording streak cameras for both diagnostics and passes through this special beam splitter on its way into the NIF vacuum chamber.

  19. Combining a thermal-imaging diagnostic with an existing imaging VISAR diagnostic at the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Malone, R; Celeste, J; Celliers, P; Frogget, B; Guyton, R L; Kaufman, M; Lee, T; MacGowan, B; Ng, E W; Reinbachs, I P; Robinson, R B; Seppala, L; Tunnell, T W; Watts, P

    2005-07-07

    Optical diagnostics are currently being designed to analyze high-energy density physics experiments at the National Ignition Facility (NIF). Two independent line-imaging Velocity Interferometer System for Any Reflector (VISAR) interferometers have been fielded to measure shock velocities, breakout times, and emission of targets having sizes of 1-5 mm. An 8-inch-diameter, fused silica triplet lens collects light at f/3 inside the 30-foot-diameter NIF vacuum chamber. VISAR recordings use a 659.5-nm probe laser. By adding a specially coated beam splitter to the interferometer table, light at wavelengths from 540 to 645 nm is spilt into a thermal-imaging diagnostic. Because fused silica lenses are used in the first triplet relay, the intermediate image planes for different wavelengths separate by considerable distances. A corrector lens on the interferometer table reunites these separated wavelength planes to provide a good image. Thermal imaging collects light at f/5 from a 2-mm object placed at Target Chamber Center (TCC). Streak cameras perform VISAR and thermal-imaging recording. All optical lenses are on kinematic mounts so that pointing accuracy of the optical axis may be checked. Counter-propagating laser beams (orange and red) are used to align both diagnostics. The red alignment laser is selected to be at the 50 percent reflection point of the beam splitter. This alignment laser is introduced at the recording streak cameras for both diagnostics and passes through this special beam splitter on its way into the NIF vacuum chamber.

  20. Imaging VISAR diagnostic for the National Ignition Facility (NIF)

    Science.gov (United States)

    Malone, Robert M.; Bower, John R.; Bradley, David K.; Capelle, Gene A.; Celeste, John R.; Celliers, Peter M.; Collins, Gilbert W.; Eckart, Mark J.; Eggert, Jon H.; Frogget, Brent C.; Guyton, Robert L.; Hicks, Damien G.; Kaufman, Morris I.; MacGowan, Brian J.; Montelongo, Samuel; Ng, Edmund W.; Robinson, Ronald B.; Tunnell, Thomas W.; Watts, Phillip W.; Zapata, Paul G.

    2005-03-01

    The National Ignition Facility (NIF) requires diagnostics to analyze high-energy density physics experiments. A VISAR (Velocity Interferometry System for Any Reflector) diagnostic has been designed to measure shock velocities, shock breakout times, and shock emission of targets with sizes from 1 to 5 mm. An 8-inch-diameter fused silica triplet lens collects light at f/3 inside the 30-foot-diameter vacuum chamber. The optical relay sends the image out an equatorial port, through a 2-inch-thick vacuum window, and into two interferometers. A 60-kW VISAR probe laser operates at 659.5 nm with variable pulse width. Special coatings on the mirrors and cutoff filters are used to reject the NIF drive laser wavelengths and to pass a band of wavelengths for VISAR, passive shock breakout light, or thermal imaging light (bypassing the interferometers). The first triplet can be no closer than 500 mm from the target chamber center and is protected from debris by a blast window that is replaced after every event. The front end of the optical relay can be temporarily removed from the equatorial port, allowing other experimenters to use that port. A unique resolution pattern has been designed to validate the VISAR diagnostic before each use. All optical lenses are on kinematic mounts so that the pointing accuracy of the optical axis can be checked. Seven CCD cameras monitor the diagnostic alignment.

  1. Imaging VISAR diagnostic for the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Malone, R M; Bower, J R; Bradley, D K; Capelle, G A; Celeste, J R; Celliers, P M; Collins, G W; Eckart, M J; Eggert, J H; Frogget, B C; Guyton, R L; Hicks, D G; Kaufman, M I; MacGowan, B J; Montelongo, S; Ng, E W; Robinson, R B; Tunnell, T W; Watts, P W; Zapata, P G

    2004-08-30

    The National Ignition Facility (NIF) requires diagnostics to analyze high-energy density physics experiments. A VISAR (Velocity Interferometry System for Any Reflector) diagnostic has been designed to measure shock velocities, shock breakout times, and shock emission of targets with sizes from 1 to 5 mm. An 8-inch-diameter fused silica triplet lens collects light at f/3 inside the 30-foot-diameter vacuum chamber. The optical relay sends the image out an equatorial port, through a 2-inch-thick vacuum window, and into two interferometers. A 60-kW VISAR probe laser operates at 659.5 nm with variable pulse width. Special coatings on the mirrors and cutoff filters are used to reject the NIF drive laser wavelengths and to pass a band of wavelengths for VISAR, passive shock breakout light, or thermal imaging light (bypassing the interferometers). The first triplet can be no closer than 500 mm from the target chamber center and is protected from debris by a blast window that is replaced after every event. The front end of the optical relay can be temporarily removed from the equatorial port, allowing other experimenters to use that port. A unique resolution pattern has been designed to validate the VISAR diagnostic before each use. All optical lenses are on kinematic mounts so that the pointing accuracy of the optical axis can be checked. Seven CCD cameras monitor the diagnostic alignment.

  2. A novel approach for a 2D/3D image registration routine for medical tool navigation in minimally invasive vascular interventions

    Energy Technology Data Exchange (ETDEWEB)

    Schwerter, Michael [Forschungszentrum Juelich (Germany). Inst. of Neuroscience and Medicine (INM-4) - Medical Imaging Physics; Lietzmann, Florian; Schad, Lothar R. [Heidelberg Univ., Medical Faculty Mannheim (Germany). Computer Assisted Clinical Medicine

    2016-11-01

    Minimally invasive interventions are frequently aided by 2D projective image guidance. To facilitate the navigation of medical tools within the patient, information from preoperative 3D images can supplement interventional data. This work describes a novel approach to perform a 3D CT data registration to a single interventional native fluoroscopic frame. The goal of this procedure is to recover and visualize a current 2D interventional tool position in its corresponding 3D dataset. A dedicated routine was developed and tested on a phantom. The 3D position of a guidewire inserted into the phantom could successfully be reconstructed for varying 2D image acquisition geometries. The scope of the routine includes projecting the CT data into the plane of the fluoroscopy. A subsequent registration of the real and virtual projections is performed with an accuracy within the range of 1.16 ± 0.17 mm for fixed landmarks. The interventional tool is extracted from the fluoroscopy and matched to the corresponding part of the projected and transformed arterial vasculature. A root mean square error of up to 0.56 mm for matched point pairs is reached. The desired 3D view is provided by backprojecting the matched guidewire through the CT array. Due to its potential to reduce patient dose and treatment times, the proposed routine has the capability of reducing patient stress at lower overall treatment costs.

  3. Full-Color Computational Imaging with Single-Pixel Detectors Based on a 2D Discrete Cosine Transform

    CERN Document Server

    Liu, Bao-Lei; Wu, Ling-An

    2016-01-01

    We propose and demonstrate a computational imaging technique that uses structured illumination based on a two-dimensional discrete cosine transform to perform imaging with a single-pixel detector. A scene is illuminated by a projector with two sets of orthogonal patterns, then by applying an inverse cosine transform to the spectra obtained from the single-pixel detector a full-color image is retrieved. This technique can retrieve an image from sub-Nyquist measurements, and the background noise is easily canceled to give excellent image quality. Moreover, the experimental setup is very simple.

  4. Parkinson's disease: diagnostic utility of volumetric imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wei-Che; Chen, Meng-Hsiang [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Diagnostic Radiology, Kaohsiung (China); Chou, Kun-Hsien [National Yang-Ming University, Brain Research Center, Taipei (China); Lee, Pei-Lin [National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China); Tsai, Nai-Wen; Lu, Cheng-Hsien [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Neurology, Kaohsiung (China); Chen, Hsiu-Ling [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Diagnostic Radiology, Kaohsiung (China); National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China); Hsu, Ai-Ling [National Taiwan University, Institute of Biomedical Electronics and Bioinformatics, Taipei (China); Huang, Yung-Cheng [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Nuclear Medicine, Kaohsiung (China); Lin, Ching-Po [National Yang-Ming University, Brain Research Center, Taipei (China); National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China)

    2017-04-15

    This paper aims to examine the effectiveness of structural imaging as an aid in the diagnosis of Parkinson's disease (PD). High-resolution T{sub 1}-weighted magnetic resonance imaging was performed in 72 patients with idiopathic PD (mean age, 61.08 years) and 73 healthy subjects (mean age, 58.96 years). The whole brain was parcellated into 95 regions of interest using composite anatomical atlases, and region volumes were calculated. Three diagnostic classifiers were constructed using binary multiple logistic regression modeling: the (i) basal ganglion prior classifier, (ii) data-driven classifier, and (iii) basal ganglion prior/data-driven hybrid classifier. Leave-one-out cross validation was used to unbiasedly evaluate the predictive accuracy of imaging features. Pearson's correlation analysis was further performed to correlate outcome measurement using the best PD classifier with disease severity. Smaller volume in susceptible regions is diagnostic for Parkinson's disease. Compared with the other two classifiers, the basal ganglion prior/data-driven hybrid classifier had the highest diagnostic reliability with a sensitivity of 74%, specificity of 75%, and accuracy of 74%. Furthermore, outcome measurement using this classifier was associated with disease severity. Brain structural volumetric analysis with multiple logistic regression modeling can be a complementary tool for diagnosing PD. (orig.)

  5. Eddy current imaging. Simplifying the direct problem. Analysis of a 2D case with formulations; Imagerie par courants de Foucault. Le probleme direct simplifie. Formulations et etude d`un cas 2D

    Energy Technology Data Exchange (ETDEWEB)

    Spineanu, A.; Zorgati, R.

    1995-12-31

    Eddy current non-destructive testing is used by EDF to detect faults affecting conductive objects such as steam generator tubes. A new technique, known as eddy current imaging, is being developed to facilitate diagnosis in this context. The first stage in this work, discussed in the present paper, consists in solving the direct problem. This entails determining the measurable quantities, on the basis of a thorough knowledge of the material considered. This was done by formulating the direct problem in terms of eddy currents in general 3D geometry context, applying distribution theory and Maxwell equations. Since no direct problem code was available we resorted to simplified situations. Taking care not to interfere with previous developments or those to be attempted in an inversion context, we studied the case of a flaw affecting a 2D structure, illuminated by a plane wave type probe. For this configuration, we studied the exact model and compared results with those of a linearized simplified model. This study emphasizes the ill-posed situation of the eddy current inverse problem related with the severe electromagnetic field attenuation. This means that regularization of the inverse problem, although absolutely necessary, will not be sufficient. Owing to the simplicity of the models available and implemented during the inversion process, processing real data would not yet be possible. We must first focus all our efforts on the direct 3 D problem, in conformity with the requirements of the inverse procedure ad describing a realistic eddy current NDT situation. At the same time, consideration should be given to the design of a specific probe customized for eddy current imaging. (authors). 9 refs., 5 figs., 3 appends.

  6. Dose and diagnostic image quality in digital tomosynthesis imaging of facial bones in pediatrics

    Science.gov (United States)

    King, J. M.; Hickling, S.; Elbakri, I. A.; Reed, M.; Wrogemann, J.

    2011-03-01

    The purpose of this study was to evaluate the use of digital tomosynthesis (DT) for pediatric facial bone imaging. We compared the eye lens dose and diagnostic image quality of DT facial bone exams relative to digital radiography (DR) and computed tomography (CT), and investigated whether we could modify our current DT imaging protocol to reduce patient dose while maintaining sufficient diagnostic image quality. We measured the dose to the eye lens for all three modalities using high-sensitivity thermoluminescent dosimeters (TLDs) and an anthropomorphic skull phantom. To assess the diagnostic image quality of DT compared to the corresponding DR and CT images, we performed an observer study where the visibility of anatomical structures in the DT phantom images were rated on a four-point scale. We then acquired DT images at lower doses and had radiologists indicate whether the visibility of each structure was adequate for diagnostic purposes. For typical facial bone exams, we measured eye lens doses of 0.1-0.4 mGy for DR, 0.3-3.7 mGy for DT, and 26 mGy for CT. In general, facial bone structures were visualized better with DT then DR, and the majority of structures were visualized well enough to avoid the need for CT. DT imaging provides high quality diagnostic images of the facial bones while delivering significantly lower doses to the lens of the eye compared to CT. In addition, we found that by adjusting the imaging parameters, the DT effective dose can be reduced by up to 50% while maintaining sufficient image quality.

  7. 2D-3D radiograph to cone-beam computed tomography (CBCT) registration for C-arm image-guided robotic surgery.

    Science.gov (United States)

    Liu, Wen Pei; Otake, Yoshito; Azizian, Mahdi; Wagner, Oliver J; Sorger, Jonathan M; Armand, Mehran; Taylor, Russell H

    2015-08-01

    C-arm radiographs are commonly used for intraoperative image guidance in surgical interventions. Fluoroscopy is a cost-effective real-time modality, although image quality can vary greatly depending on the target anatomy. Cone-beam computed tomography (CBCT) scans are sometimes available, so 2D-3D registration is needed for intra-procedural guidance. C-arm radiographs were registered to CBCT scans and used for 3D localization of peritumor fiducials during a minimally invasive thoracic intervention with a da Vinci Si robot. Intensity-based 2D-3D registration of intraoperative radiographs to CBCT was performed. The feasible range of X-ray projections achievable by a C-arm positioned around a da Vinci Si surgical robot, configured for robotic wedge resection, was determined using phantom models. Experiments were conducted on synthetic phantoms and animals imaged with an OEC 9600 and a Siemens Artis zeego, representing the spectrum of different C-arm systems currently available for clinical use. The image guidance workflow was feasible using either an optically tracked OEC 9600 or a Siemens Artis zeego C-arm, resulting in an angular difference of Δθ:∼ 30°. The two C-arm systems provided TRE mean ≤ 2.5 mm and TRE mean ≤ 2.0 mm, respectively (i.e., comparable to standard clinical intraoperative navigation systems). C-arm 3D localization from dual 2D-3D registered radiographs was feasible and applicable for intraoperative image guidance during da Vinci robotic thoracic interventions using the proposed workflow. Tissue deformation and in vivo experiments are required before clinical evaluation of this system.

  8. 2-D scanning technology in passive terahertz imaging%被动太赫兹成像二维扫描技术

    Institute of Scientific and Technical Information of China (English)

    谢巍; 侯丽伟; 潘鸣

    2014-01-01

    It is inevitable to use 2-D scanning in wide-Field of View(FOV) terahertz imaging due to the restriction of terahertz detector(lack of pixels and hardly integrated to large-scale plane array). The 45° mirror could be used in passive terahertz 2-D scanning imaging for its advantages in dimension, stability and scanning Field of View. The principle of 2-D scanning imaging using 45° mirror is analyzed in detail. A new method with horizontal scanning by rotating around axis Zand vertical stepping by rotating around axis Yis proposed. The scanning trace is calculated, the margin FOV distortion is about 3.2%. The method is validated by the imaging experiment and image is acquired in wide-Field of View.%太赫兹成像受探测器像元数少和无法进行大规模面阵集成的限制,大视场成像不可避免地要用到二维扫描。45º镜具有尺寸小,稳定性好,幅宽大等特点,可以用来实现被动太赫兹二维扫描成像。详细分析了45º镜扫描成像的工作原理和扫描方式,提出了绕Z轴摆动实现水平扫描,绕Y轴摆动实现垂直步进的扫描方案,计算了扫描轨迹,边沿视场成像畸变约3.2%,并通过成像实验对扫描方案进行了验证,得到了大视场下的被动太赫兹二维扫描图像。

  9. A Volume Rendering Algorithm for Sequential 2D Medical Images%序列二维医学图象的体绘制法

    Institute of Scientific and Technical Information of China (English)

    吕忆松; 陈亚珠

    2002-01-01

    Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics. To help physicians fully understand deep-seated human organs and focuses (e. g. a tumnout) as 3D structures, in this paper, we present a modified volume rendering algorithm to render volumetric data. Using this method, the projection images of structures of interest from different viewing directions can be obtained satisfactorily. By rotating the light source and the observer eyepoint, this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time. Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.

  10. Contrast-enhanced MR Imaging of Metastatic Brain Tumor at 3 Tesla: Utility of T1-weighted SPACE Compared with 2D Spin Echo and 3D Gradient Echo Sequence

    National Research Council Canada - National Science Library

    KOMADA, Tomohiro; NAGANAWA, Shinji; OGAWA, Hiroshi; MATSUSHIMA, Masaya; KUBOTA, Seiji; KAWAI, Hisashi; FUKATSU, Hiroshi; IKEDA, Mitsuru; KAWAMURA, Minako; SAKURAI, Yasuo; MARUYAMA, Katsuya

    2008-01-01

    ...), and 2-dimensional T1-weighted spin echo (2D-SE) imaging at 3T. We quantitatively compared SPACE, MP-RAGE, and 2D-SE images by using signal-to-noise ratios (SNRs) for gray matter (GM) and white matter (WM...

  11. OUT-OF-FOCUS REGION SEGMENTATION OF 2D SURFACE IMAGES WITH THE USE OF TEXTURE FEATURES

    Directory of Open Access Journals (Sweden)

    K. Anding

    2015-09-01

    Full Text Available A segmentation method of out-of-focus image regions for processed metal surfaces, based on focus textural features is proposed. Such regions contain small amount of useful information. The object of study is a metal surface, which has a cone shape. Some regions of images are blurred because the depth of field of industrial cameras is limited. Automatic removal of out-of-focus regions in such images is one of the possible solutions to this problem. Focus texture features were used to calculate characteristics that describe the sharpness of particular image area. Such features are used in autofocus systems of microscopes and cameras, and their application for segmentation of out-of-focus regions of images is unusual. Thirty-four textural features were tested on a set of metal surface images with out-of-focus regions. The most useful features, usable for segmentation of an image more accurately, are an average grey level and spatial frequency. Proposed segmentation method of out-of-focus image regions for metal surfaces can be successfully applied for evaluation of processing quality of materials with the use of industrial cameras. The method has simple implementation and high calculating speed.

  12. Strategic planning for radiology: opening an outpatient diagnostic imaging center.

    Science.gov (United States)

    Leepson, Evan

    2003-01-01

    Launching a new diagnostic imaging center involves very specific requirements and roadmaps, including five major areas of change that have a direct impact on planning: Imaging and communication technology Finances and reimbursement Ownership structure of imaging entities Critical workforce shortages Imaging is moving outside radiology First, planning must focus on the strategic level of any organization, whether it is a multi-national corporation or a six-person radiology group. Think of all organizations as a triangle with three horizontal levels: strategic, managerial and operational. The strategic level of decision-making is at the top of the triangle, and here is where planning must take place. For strategic planning to work, there must be focused time and energy spent on this activity, usually away from the reading room and imaging center. There are five planning strategies, which must have the explicit goal of developing and growing the imaging center. The five strategies are: Clinical and quality issues, Governance and administration, Technology, Relationships, Marketing and business development. The best way to plan and implement these strategies is to create work groups of radiologists, technologists, and administrative and support staff. Once the group agrees on the strategy and tactic, it takes responsibility for implementation. Embarking on the launch of a new outpatient diagnostic imaging center is no small undertaking, and anyone who has struggled with such an endeavor can readily attest to the associated challenges and benefits. Success depends on many things, and one of the most important factors relates to the amount of time and the quality of effort spent on strategic planning at the outset. Neglecting or skimping on this phase may lead to unforeseen obstacles that could potentially derail the project.

  13. Holographic intravital microscopy for 2-D and 3-D imaging intact circulating blood cells in microcapillaries of live mice

    CERN Document Server

    Kim, Kyoohyun; Park, Inwon; Kim, Pilhan; Park, YongKeun

    2016-01-01

    Intravital microscopy is an essential tool that reveals behaviours of live cells under conditions close to natural physiological states. So far, although various approaches for imaging cells in vivo have been proposed, most require the use of labelling and also provide only qualitative imaging information. Holographic imaging approach based on measuring the refractive index distributions of cells, however, circumvent these problems and offer quantitative and label-free imaging capability. Here, we demonstrate in vivo two- and three-dimensional holographic imaging of circulating blood cells in intact microcapillaries of live mice. The measured refractive index distributions of blood cells provide morphological and biochemical properties including three-dimensional cell shape, haemoglobin concentration, and haemoglobin contents at the individual cell level. With the present method, alterations in blood flow dynamics in live healthy and sepsis-model mouse were also investigated.

  14. Holographic intravital microscopy for 2-D and 3-D imaging intact circulating blood cells in microcapillaries of live mice

    Science.gov (United States)

    Kim, Kyoohyun; Choe, Kibaek; Park, Inwon; Kim, Pilhan; Park, Yongkeun

    2016-09-01

    Intravital microscopy is an essential tool that reveals behaviours of live cells under conditions close to natural physiological states. So far, although various approaches for imaging cells in vivo have been proposed, most require the use of labelling and also provide only qualitative imaging information. Holographic imaging approach based on measuring the refractive index distributions of cells, however, circumvent these problems and offer quantitative and label-free imaging capability. Here, we demonstrate in vivo two- and three-dimensional holographic imaging of circulating blood cells in intact microcapillaries of live mice. The measured refractive index distributions of blood cells provide morphological and biochemical properties including three-dimensional cell shape, haemoglobin concentration, and haemoglobin contents at the individual cell level. With the present method, alterations in blood flow dynamics in live healthy and sepsis-model mice were also investigated.

  15. Exact monitoring of aortic diameters in Marfan patients without gadolinium contrast: intraindividual comparison of 2D SSFP imaging with 3D CE-MRA and echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Simon [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany); University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Behzadi, Cyrus; Derlin, Thorsten; Henes, Frank Oliver; Adam, Gerhard; Bannas, Peter [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Rybczinsky, Meike; Kodolitsch, Yskert von; Sheikhzadeh, Sara [University Medical Center Hamburg-Eppendorf, Department of General and Interventional Cardiology, Hamburg (Germany); Bley, Thorsten Alexander [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany)

    2014-10-15

    To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison. Non-ECG-gated CE-MRA and ECG-gated non-contrast SSFP at 1.5 T were prospectively performed in 50 patients. Two readers measured aortic diameters on para-sagittal images identically aligned with the aortic arch at the sinuses of Valsalva, sinotubular junction, ascending/descending aorta and aortic arch. Image quality was assessed on a three-point scale. Aortic root diameters acquired by echocardiography were used as reference. Intra- and interobserver variances were smaller for SSFP at the sinuses of Valsalva (p = 0.002; p = 0.002) and sinotubular junction (p = 0.014; p = 0.043). Image quality was better in SSFP than in CE-MRA at the sinuses of Valsalva (p < 0.0001), sinotubular junction (p < 0.0001) and ascending aorta (p = 0.02). CE-MRA yielded higher diameters than SSFP at the sinuses of Valsalva (mean bias, 2.5 mm; p < 0.0001), and comparison with echocardiography confirmed a higher bias for CE-MRA (7.2 ± 3.4 mm vs. SSFP, 4.7 ± 2.6 mm). ECG-gated non-contrast 2D SSFP imaging provides superior image quality with higher validity compared to non-ECG-gated contrast-enhanced 3D imaging. Since CE-MRA requires contrast agents with potential adverse effects, non-contrast SSFP imaging is an appropriate alternative for exact and riskless aortic monitoring of MFS patients. (orig.)

  16. The diagnostic accuracy of MR imaging in osteoid osteoma

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Mark; Cassar-Pullicino, Victor N.; McCall, Iain W.; Tyrrell, Prudencia N.M. [Department of Radiology, The Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire, SY10 7AG (United Kingdom); Davies, Mark A. [The MRI Centre, Royal Orthopaedic Hospital, Birmingham (United Kingdom)

    2002-10-01

    To analyse the MR imaging appearances of a large series of osteoid osteomas, to assess the ability of MR imaging to detect the tumour, and to identify potential reasons for misdiagnosis.Design and patients. The MR imaging findings of 43 patients with osteoid osteoma were reviewed retrospectively and then compared with other imaging modalities to assess the accuracy of MR localisation and interpretation.Results. The potential for a missed diagnosis was 35% based solely on the MR investigations. This included six tumours which were not seen and nine which were poorly visualised. The major determinants of the diagnostic accuracy of MR imaging were the MR technique, skeletal location, and preliminary radiographic appearances. There was a wide spectrum of MR signal appearances of the lesion. The tumour was identified in 65% of sequences performed in the axial plane. The nidus was present in only one slice of the optimal sequence in 27 patients. Reactive bone changes were present in 33 and soft tissue changes in 37 patients.Conclusion. Reliance on MR imaging alone may lead to misdiagnosis. As the osteoid osteoma may be difficult to identify and the MR features easily misinterpreted, optimisation of MR technique is crucial in reducing the risk of missing the diagnosis. Unexplained areas of bone marrow oedema in particular require further imaging (scintigraphy and CT) to exclude an osteoid osteoma. (orig.)

  17. Sensor fusion of 2D and 3D data for the processing of images of dental imprints

    Science.gov (United States)

    Methot, Jean-Francois; Mokhtari, Marielle; Laurendeau, Denis; Poussart, Denis

    1993-08-01

    This paper presents a computer vision system for the acquisition and processing of 3-D images of wax dental imprints. The ultimate goal of the system is to measure a set of 10 orthodontic parameters that will be fed to an expert system for automatic diagnosis of occlusion problems. An approach for the acquisition of range images of both sides of the imprint is presented. Range is obtained from a shape-from-absorption technique applied to a pair of grey-level images obtained at two different wavelengths. The accuracy of the range values is improved using sensor fusion between the initial range image and a reflectance image from the pair of grey-level images. The improved range image is segmented in order to find the interstices between teeth and, following further processing, the type of each tooth on the profile. Once each tooth has been identified, its accurate location on the imprint is found using a region- growing approach and its shape is reconstructed with third degree polynomial functions. The reconstructed shape will be later used by the system to find specific features that are needed to estimate the orthodontic parameters.

  18. Efficient transmission of 1D and 2D chaotic map encrypted images with orthogonal frequency division multiplexing

    Science.gov (United States)

    Kasem, Hossam M.; Nasr, Mohamed E.; Sallam, Elsayed A.; Abd El-Samie, F. E.

    2011-10-01

    Image transmission takes place as an important research branch in multimedia broadcasting communication systems in the last decade. Our paper presents image transmission over a FFT-OFDM (Fast Fourier Transform Orthogonal Frequency Division Multiplexing). The need for encryption techniques increase with the appearance of the expression which said that our world became small village, and the use of image application such as conference and World Wide Web which increase rapidly in recent years. Encryption is an effective method for protecting the transmitted data by converting it into a form being invisible over transmission path and visible in receiver side. This paper presents a new hybrid encryption technique based on combination of Backer maps and logistic map. This proposed technique aims to increase PSNR and reduce the noise in the received image. The encryption is done by shuffling the positions of a pixel image using two dimensional Baker maps then encrypt using XOR operation with logistic map to generate cipher image over orthogonal frequency multiplexing (OFDM). The encryption approach adopted in this paper is based on chaotic Baker maps because the encoding and decoding steps in this approach are simple and fast enough for HDTV applications. The experimental results reveal the superiority of the proposed chaotic based image encryption technique using two logistic maps and two dimensional Backer map over normal Backer map.

  19. Accuracy of diagnostic imaging in nephroblastoma before preoperative chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rieden, K. [Radiologische Klinik, Abt. Klinische Radiologie, Heidelberg (Germany); Weirich, A. [Kinderklinik, Univ. of Heidelberg (Germany); Troeger, J. [Radiologische Klinik, Abt. Paediatrische Radiologie, Univ. of Heidelberg (Germany); Gamroth, A.H. [Deutsches Krebsforschungszentrum, Heidelberg (Germany); Raschke, K. [Radiologische Klinik, Abt. Paediatrische Radiologie, Univ. of Heidelberg (Germany); Ludwig, R. [Kinderklinik, Univ. of Heidelberg (Germany)

    1993-04-01

    From July 1988 to February 1991, 130 children with the tentative diagnosis of nephroblastoma were treated preoperatively. The initial diagnostic images (excretory urography, ultrasound, CT, MRI) have been analysed both prospectively and retrospectively and the findings correlated with the intraoperative and histological results. Of the preoperatively treated patients 93.8% had a Wilms` tumour or one of its variants. Five patients had a different malignant tumour and 3 patients, i.e. 2.3% of those preoperatively treated or 1.6% of all registered patients, had benign tumours of the kidney. Wilms` tumour generally presented as a well-defined mass with an inhomogeneous morphology on CT. On ultrasound only 24% of the tumours were homogeneous. Intratumoral haemorrhage and cystic areas occurred frequently; calcifications were rare (8%). With regard to caval involvement only ultrasound and MRI enabled the correct diagnosis, while CT could not differentiate compressions from invasion. The pretherapeutic diagnostic imaging was of sufficient accuracy to start preoperative chemotherapy without diagnostic biopsy. (orig.)

  20. Application of aptamers in diagnostics, drug-delivery and imaging

    Indian Academy of Sciences (India)

    CHETAN CHANDOLA; SHEETAL KALME; MARCO G CASTELEIJN; ARTO URTTI; MUNIASAMY NEERATHILINGAM

    2016-09-01

    Aptamers are small, single-stranded oligonucleotides (DNA or RNA) that bind to their target with high specificity andaffinity. Although aptamers are analogous to antibodies for a wide range of target recognition and variety ofapplications, they have significant advantages over antibodies. Since aptamers have recently emerged as a class ofbiomolecules with an application in a wide array of fields, we need to summarize the latest developments herein. Inthis review we will discuss about the latest developments in using aptamers in diagnostics, drug delivery and imaging.We begin with diagnostics, discussing the application of aptamers for the detection of infective agents itself, antigens/toxins (bacteria), biomarkers (cancer), or a combination. The ease of conjugation and labelling of aptamers makesthem a potential tool for diagnostics. Also, due to the reduced off-target effects of aptamers, their use as a potentialdrug delivery tool is emerging rapidly. Hence, we discuss their use in targeted delivery in conjugation with siRNAs,nanoparticles, liposomes, drugs and antibodies. Finally, we discuss about the conjugation strategies applicable forRNA and DNA aptamers for imaging. Their stability and self-assembly after heating makes them superior overprotein-based binding molecules in terms of labelling and conjugation strategies.

  1. Malware Memory Analysis for Non-specialists: Investigating Publicly Available Memory Image 0zapftis (R2D2)

    Science.gov (United States)

    2013-10-01

    images, the author is of the opinion that these analyses are insufficient for use as a learning guide. Specifically, these analyses are either too...serviront de guide d’apprentissage. Bien que d’autres aient mentionné avoir effectué l’analyse de ces images mémoires publiques , l’auteur croit que ces...Specifically, in order to gain practical experience analysing memory images, the author is of the opinion that there is no substitute for applying keen

  2. Choice of diagnostic and therapeutic imaging in periodontics and implantology.

    Science.gov (United States)

    Chakrapani, Swarna; Sirisha, K; Srilalitha, Anumadi; Srinivas, Moogala

    2013-11-01

    Imaging forms an integral component for diagnosis of dental and in specific periodontal diseases. To date, intra-oral radiographic techniques are the main non-invasive diagnostic aids for the detection and assessment of internal changes in mineralized periodontal tissues like alveolar bone. These analog radiographic techniques suffer from inherent limitations like: Two dimensional projection, magnification, distortion, superimposition and misrepresentation of anatomic structures. The evolution of novel imaging modalities, namely cone beam computed tomography, tuned aperture CT empowered dental researchers to visualize the periodontium three dimensionally. This improves interpretation of structural and biophysical changes, ensures densitometric assessments of dentoalveolar structures including variations in alveolar bone density, and peri-implant bone healing more precisely. This detailed review, highlights current leading edge concepts, envisions a wide range of imaging modalities which pave the way for better understanding and early intervention of periodontal diseases.

  3. Assessment of a 2D electronic portal imaging devices-based dosimetry algorithm for pretreatment and in-vivo midplane dose verification

    Science.gov (United States)

    Jomehzadeh, Ali; Shokrani, Parvaneh; Mohammadi, Mohammad; Amouheidari, Alireza

    2016-01-01

    Background: The use of electronic portal imaging devices (EPIDs) is a method for the dosimetric verification of radiotherapy plans, both pretreatment and in vivo. The aim of this study is to test a 2D EPID-based dosimetry algorithm for dose verification of some plans inside a homogenous and anthropomorphic phantom and in vivo as well. Materials and Methods: Dose distributions were reconstructed from EPID images using a 2D EPID dosimetry algorithm inside a homogenous slab phantom for a simple 10 × 10 cm2 box technique, 3D conformal (prostate, head-and-neck, and lung), and intensity-modulated radiation therapy (IMRT) prostate plans inside an anthropomorphic (Alderson) phantom and in the patients (one fraction in vivo) for 3D conformal plans (prostate, head-and-neck and lung). Results: The planned and EPID dose difference at the isocenter, on an average, was 1.7% for pretreatment verification and less than 3% for all in vivo plans, except for head-and-neck, which was 3.6%. The mean γ values for a seven-field prostate IMRT plan delivered to the Alderson phantom varied from 0.28 to 0.65. For 3D conformal plans applied for the Alderson phantom, all γ1% values were within the tolerance level for all plans and in both anteroposterior and posteroanterior (AP-PA) beams. Conclusion: The 2D EPID-based dosimetry algorithm provides an accurate method to verify the dose of a simple 10 × 10 cm2 field, in two dimensions, inside a homogenous slab phantom and an IMRT prostate plan, as well as in 3D conformal plans (prostate, head-and-neck, and lung plans) applied using an anthropomorphic phantom and in vivo. However, further investigation to improve the 2D EPID dosimetry algorithm for a head-and-neck case, is necessary. PMID:28028511

  4. A Phase Noise Analysis Method for Millimeter-Wave Passive Imager BHU-2D-U Frequency Synthesizer

    OpenAIRE

    Jin Zhang; Cheng Zheng; Xianxun Yao; Baohua Yang

    2013-01-01

    A nontrivial phase noise analysis method is proposed for frequency synthesizer of a passive millimeter-wave synthetic aperture interferometric radiometer (SAIR) imager for concealed weapon detections on human bodies with high imaging rates. The frequency synthesizer provides local oscillator signals for both millimeter-wave front ends and intermediate frequency IQ demodulators for the SAIR system. The influence of synthesizer phase noise in different offset frequency ranges on the visibility ...

  5. FIRE: an open-software suite for real-time 2D/3D image registration for image guided radiotherapy research

    Science.gov (United States)

    Furtado, H.; Gendrin, C.; Spoerk, J.; Steiner, E.; Underwood, T.; Kuenzler, T.; Georg, D.; Birkfellner, W.

    2016-03-01

    Radiotherapy treatments have changed at a tremendously rapid pace. Dose delivered to the tumor has escalated while organs at risk (OARs) are better spared. The impact of moving tumors during dose delivery has become higher due to very steep dose gradients. Intra-fractional tumor motion has to be managed adequately to reduce errors in dose delivery. For tumors with large motion such as tumors in the lung, tracking is an approach that can reduce position uncertainty. Tumor tracking approaches range from purely image intensity based techniques to motion estimation based on surrogate tracking. Research efforts are often based on custom designed software platforms which take too much time and effort to develop. To address this challenge we have developed an open software platform especially focusing on tumor motion management. FLIRT is a freely available open-source software platform. The core method for tumor tracking is purely intensity based 2D/3D registration. The platform is written in C++ using the Qt framework for the user interface. The performance critical methods are implemented on the graphics processor using the CUDA extension. One registration can be as fast as 90ms (11Hz). This is suitable to track tumors moving due to respiration (~0.3Hz) or heartbeat (~1Hz). Apart from focusing on high performance, the platform is designed to be flexible and easy to use. Current use cases range from tracking feasibility studies, patient positioning and method validation. Such a framework has the potential of enabling the research community to rapidly perform patient studies or try new methods.

  6. Physical therapist practice and the role of diagnostic imaging.

    Science.gov (United States)

    Boyles, Robert E; Gorman, Ira; Pinto, Daniel; Ross, Michael D

    2011-11-01

    For healthcare providers involved in the management of patients with musculoskeletal disorders, the ability to order diagnostic imaging is a beneficial adjunct to screening for medical referral and differential diagnosis. A trial of conservative treatment, such as physical therapy, is often recommended prior to the use of imaging in many treatment guidelines for the management of musculoskeletal conditions. In the United States, physical therapists are becoming more autonomous and can practice some degree of direct access in 48 states and Washington, DC. Referral for imaging privileges could increase the effectiveness and efficiency of healthcare delivery, particularly in combination with direct access management. This clinical commentary proposes that, given the American Physical Therapy Association's goal to have physical therapists as primary care musculoskeletal specialists of choice, it would be beneficial for physical therapists to have imaging privileges in their practice. The purpose of this commentary is 3-fold: (1) to make a case for the use of imaging privileges by physical therapists, using a historical perspective; (2) to discuss the barriers preventing physical therapists from having this privilege; and (3) to offer suggestions on strategies and guidelines to facilitate the appropriate inclusion of referral for imaging privileges in physical therapist practice. J Orthop Sports Phys Ther 2011;41(11):829-837. doi:10.2519/jospt.2011.3556.

  7. SU-E-J-13: Six Degree of Freedom Image Fusion Accuracy for Cranial Target Localization On the Varian Edge Stereotactic Radiosurgery System: Comparison Between 2D/3D and KV CBCT Image Registration

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H [Wayne State University, Detroit, MI (United States); Song, K; Chetty, I; Kim, J [Henry Ford Health System, Detroit, MI (United States); Wen, N [Henry Ford Health System, West Bloomfield, MI (United States)

    2015-06-15

    Purpose: To determine the 6 degree of freedom systematic deviations between 2D/3D and CBCT image registration with various imaging setups and fusion algorithms on the Varian Edge Linac. Methods: An anthropomorphic head phantom with radio opaque targets embedded was scanned with CT slice thicknesses of 0.8, 1, 2, and 3mm. The 6 DOF systematic errors were assessed by comparing 2D/3D (kV/MV with CT) with 3D/3D (CBCT with CT) image registrations with different offset positions, similarity measures, image filters, and CBCT slice thicknesses (1 and 2 mm). The 2D/3D registration accuracy of 51 fractions for 26 cranial SRS patients was also evaluated by analyzing 2D/3D pre-treatment verification taken after 3D/3D image registrations. Results: The systematic deviations of 2D/3D image registration using kV- kV, MV-kV and MV-MV image pairs were within ±0.3mm and ±0.3° for translations and rotations with 95% confidence interval (CI) for a reference CT with 0.8 mm slice thickness. No significant difference (P>0.05) on target localization was observed between 0.8mm, 1mm, and 2mm CT slice thicknesses with CBCT slice thicknesses of 1mm and 2mm. With 3mm CT slice thickness, both 2D/3D and 3D/3D registrations performed less accurately in longitudinal direction than thinner CT slice thickness (0.60±0.12mm and 0.63±0.07mm off, respectively). Using content filter and using similarity measure of pattern intensity instead of mutual information, improved the 2D/3D registration accuracy significantly (P=0.02 and P=0.01, respectively). For the patient study, means and standard deviations of residual errors were 0.09±0.32mm, −0.22±0.51mm and −0.07±0.32mm in VRT, LNG and LAT directions, respectively, and 0.12°±0.46°, −0.12°±0.39° and 0.06°±0.28° in RTN, PITCH, and ROLL directions, respectively. 95% CI of translational and rotational deviations were comparable to those in phantom study. Conclusion: 2D/3D image registration provided on the Varian Edge radiosurgery, 6 DOF

  8. Large-area full field x-ray differential phase-contrast imaging using 2D tiled gratings

    Science.gov (United States)

    Schröter, Tobias J.; Koch, Frieder J.; Kunka, Danays; Meyer, Pascal; Tietze, Sabrina; Engelhardt, Sabine; Zuber, Marcus; Baumbach, Tilo; Willer, Konstantin; Birnbacher, Lorenz; Prade, Friedrich; Pfeiffer, Franz; Reichert, Klaus-Martin; Hofmann, Andreas; Mohr, Jürgen

    2017-06-01

    Grating-based x-ray differential phase-contrast imaging (DPCI) is capable of acquiring information based on phase-shift and dark-field signal, in addition to conventional x-ray absorption-contrast. Thus DPCI gives an advantage to investigate composite materials with component wise similar absorption properties like soft tissues. Due to technological challenges in fabricating high quality gratings over a large extent, the field of view (FoV) of the imaging systems is limited to a grating area of a couple of square centimeters. For many imaging applications (e.g. in medicine), however, a FoV that ranges over several ten centimeters is needed. In this manuscript we propose to create large area gratings of theoretically any extent by assembling a number of individual grating tiles. We discuss the precision needed for alignment of each microstructure tile in order to reduce image artifacts and to preserve minimum 90% of the sensitivity obtainable with a monolithic grating. To achieve a reliable high precision alignment a semiautomatic assembly system consisting of a laser autocollimator, a digital microscope and a force sensor together with positioning devices was built. The setup was used to tile a first four times four analyzer grating with a size of 200 mm  ×  200 mm together with a two times two phase grating. First imaging results prove the applicability and quality of the tiling concept.

  9. CT imaging in acute pulmonary embolism: diagnostic strategies

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, Joachim E.; Mahnken, Andreas H.; Das, Marco; Guenther, Rolf W. [University of Technology (RWTH), Department of Diagnostic Radiology, University Hospital, Aachen (Germany); Kuettner, Axel [Eberhard Karls University, Department of Diagnostic Radiology, Tuebingen (Germany); Lell, Michael [Friedrich Alexander University, Department of Diagnostic Radiology, Erlangen (Germany)

    2005-05-01

    Computed tomography pulmonary angiography (CTA) has increasingly become accepted as a widely available, safe, cost-effective, and accurate method for a quick and comprehensive diagnosis of acute pulmonary embolism (PE). Pulmonary catheter angiography is still considered the gold standard and final imaging method in many diagnostic algorithms. However, spiral CTA has become established as the first imaging test in clinical routine due to its high negative predictive value for clinically relevant PE. Despite the direct visualization of clot material, depiction of cardiac and pulmonary function in combination with the quantification of pulmonary obstruction helps to grade the severity of PE for further risk stratification and to monitor the effect of thrombolytic therapy. Because PE and deep venous thrombosis are two different aspects of the same disease, additional indirect CT venography may be a valuable addition to the initial diagnostic algorithm - if this was positive for PE - and demonstration of the extent and localization of deep venous thrombosis has an impact on clinical management. Additional and alternate diagnoses add to the usefulness of this method. Using advanced multislice spiral CT technology, some practitioners have advocated CTA as the sole imaging tool for routine clinical assessment in suspected acute PE. This will simplify standards of practice in the near future. (orig.)

  10. Australian per caput dose from diagnostic imaging and nuclear medicine.

    Science.gov (United States)

    Hayton, A; Wallace, A; Marks, P; Edmonds, K; Tingey, D; Johnston, P

    2013-10-01

    The largest man-made contributor to the ionising radiation dose to the Australian population is from diagnostic imaging and nuclear medicine. The last estimation of this dose was made in 2004 (1.3 mSv), this paper describes a recent re-evaluation of this dose to reflect the changes in imaging trends and technology. The estimation was calculated by summing the dose from five modalities, computed tomography (CT), general radiography/fluoroscopy, interventional procedures, mammography and nuclear medicine. Estimates were made using Australian frequency data and dose data from a range of Australian and international sources of average effective dose values. The ionising radiation dose to the Australian population in 2010 from diagnostic imaging and nuclear medicine is estimated to be 1.7 mSv (1.11 mSv CT, 0.30 mSv general radiography/fluoroscopy, 0.17 mSv interventional procedures, 0.03 mSv mammography and 0.10 mSv nuclear medicine). This exceeds the estimate of 1.5 mSv per person from natural background and cosmic radiation.

  11. Diagnostic imaging, a "parallel" discipline. Can current technology provide a reliable digital diagnostic radiology department?

    Science.gov (United States)

    Moore, C J; Eddleston, B

    1985-04-01

    Only recently has any detailed criticism been voiced about the practicalities of the introduction of generalised, digital, imaging complexes in diagnostic radiology. Although attendant technological problems are highlighted we argue that the fundamental causes of current difficulties are not in the generation but in the processing, filing and subsequent retrieval for display of digital image records. In the real world, looking at images is a parallel process of some complexity and so it is perhaps untimely to expect versatile handling of vast image data bases by existing computer hardware and software which, by their current nature, perform tasks serially. Successes in applying new imaging devices using digital technology, numerical methods and more easily available computing power are directing radiology towards the concept of all-digital departmental complexes. Hence a critical discussion of fundamental problems should be encouraged, to promote a thorough understanding of what may be involved (Gray et al, 1984) in following such a course. It is equally important to gain some perspective about the development possibilities for existing, commercially available equipment being offered to the medical community.

  12. A novel method to acquire 3D data from serial 2D images of a dental cast

    Science.gov (United States)

    Yi, Yaxing; Li, Zhongke; Chen, Qi; Shao, Jun; Li, Xinshe; Liu, Zhiqin

    2007-05-01

    This paper introduced a newly developed method to acquire three-dimensional data from serial two-dimensional images of a dental cast. The system consists of a computer and a set of data acquiring device. The data acquiring device is used to take serial pictures of the a dental cast; an artificial neural network works to translate two-dimensional pictures to three-dimensional data; then three-dimensional image can reconstruct by the computer. The three-dimensional data acquiring of dental casts is the foundation of computer-aided diagnosis and treatment planning in orthodontics.

  13. High spatiotemporal resolution measurement of regional lung air volumes from 2D phase contrast x-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Leong, Andrew F. T.; Islam, M. Sirajul; Kitchen, Marcus J. [School of Physics, Monash University, Victoria 3800 (Australia); Fouras, Andreas [Division of Biological Engineering, Monash University, Victoria 3800 (Australia); Wallace, Megan J.; Hooper, Stuart B. [Ritchie Centre and Department of Obstetrics and Gynaecology, Monash Institute of Medical Research, Monash University, Victoria 3168 (Australia)

    2013-04-15

    Purpose: Described herein is a new technique for measuring regional lung air volumes from two-dimensional propagation-based phase contrast x-ray (PBI) images at very high spatial and temporal resolution. Phase contrast dramatically increases lung visibility and the outlined volumetric reconstruction technique quantifies dynamic changes in respiratory function. These methods can be used for assessing pulmonary disease and injury and for optimizing mechanical ventilation techniques for preterm infants using animal models. Methods: The volumetric reconstruction combines the algorithms of temporal subtraction and single image phase retrieval (SIPR) to isolate the image of the lungs from the thoracic cage in order to measure regional lung air volumes. The SIPR algorithm was used to recover the change in projected thickness of the lungs on a pixel-by-pixel basis (pixel dimensions {approx}16.2 {mu}m). The technique has been validated using numerical simulation and compared results of measuring regional lung air volumes with and without the use of temporal subtraction for removing the thoracic cage. To test this approach, a series of PBI images of newborn rabbit pups mechanically ventilated at different frequencies was employed. Results: Regional lung air volumes measured from PBI images of newborn rabbit pups showed on average an improvement of at least 20% in 16% of pixels within the lungs in comparison to that measured without the use of temporal subtraction. The majority of pixels that showed an improvement was found to be in regions occupied by bone. Applying the volumetric technique to sequences of PBI images of newborn rabbit pups, it is shown that lung aeration at birth can be highly heterogeneous. Conclusions: This paper presents an image segmentation technique based on temporal subtraction that has successfully been used to isolate the lungs from PBI chest images, allowing the change in lung air volume to be measured over regions as small as the pixel size. Using

  14. Computation of 2-D pinhole image-formation process of large-scale furnaces using the discrete ordinates method

    CERN Document Server

    Li Hong; Lu Ji Dong; Zheng Chu Guan

    2003-01-01

    In most of the discrete ordinate schemes (DOS) reported in the literature, the discrete directions are fixed, and unable to be arbitrarily adjusted; therefore, it is difficult to employ these schemes to calculate the radiative energy image-formation of pulverized-coal furnaces. On the basis of a new DOS, named the discrete ordinate scheme with (an) infinitely small weight(s), which was recently proposed by the authors, a novel algorithm for computing the pinhole image-formation process is developed in this work. The performance of this algorithm is tested, and is found to be also suitable for parallel computation.

  15. Fast ion induced shearing of 2D Alfvén eigenmodes measured by electron cyclotron emission imaging.

    Science.gov (United States)

    Tobias, B J; Classen, I G J; Domier, C W; Heidbrink, W W; Luhmann, N C; Nazikian, R; Park, H K; Spong, D A; Van Zeeland, M A

    2011-02-18

    Two-dimensional images of electron temperature perturbations are obtained with electron cyclotron emission imaging (ECEI) on the DIII-D tokamak and compared to Alfvén eigenmode structures obtained by numerical modeling using both ideal MHD and hybrid MHD-gyrofluid codes. While many features of the observations are found to be in excellent agreement with simulations using an ideal MHD code (NOVA), other characteristics distinctly reveal the influence of fast ions on the mode structures. These features are found to be well described by the nonperturbative hybrid MHD-gyrofluid model TAEFL.

  16. 3D-2D image registration for target localization in spine surgery: investigation of similarity metrics providing robustness to content mismatch

    Science.gov (United States)

    De Silva, T.; Uneri, A.; Ketcha, M. D.; Reaungamornrat, S.; Kleinszig, G.; Vogt, S.; Aygun, N.; Lo, S.-F.; Wolinsky, J.-P.; Siewerdsen, J. H.

    2016-04-01

    In image-guided spine surgery, robust three-dimensional to two-dimensional (3D-2D) registration of preoperative computed tomography (CT) and intraoperative radiographs can be challenged by the image content mismatch associated with the presence of surgical instrumentation and implants as well as soft-tissue resection or deformation. This work investigates image similarity metrics in 3D-2D registration offering improved robustness against mismatch, thereby improving performance and reducing or eliminating the need for manual masking. The performance of four gradient-based image similarity metrics (gradient information (GI), gradient correlation (GC), gradient information with linear scaling (GS), and gradient orientation (GO)) with a multi-start optimization strategy was evaluated in an institutional review board-approved retrospective clinical study using 51 preoperative CT images and 115 intraoperative mobile radiographs. Registrations were tested with and without polygonal masks as a function of the number of multistarts employed during optimization. Registration accuracy was evaluated in terms of the projection distance error (PDE) and assessment of failure modes (PDE  >  30 mm) that could impede reliable vertebral level localization. With manual polygonal masking and 200 multistarts, the GC and GO metrics exhibited robust performance with 0% gross failures and median PDE  registration to fail at a rate of  >14% however, GO maintained robustness with a 0% gross failure rate. Overall, the GI, GC, and GS metrics were susceptible to registration errors associated with content mismatch, but GO provided robust registration (median PDE  =  5.5 mm, 2.6 mm IQR) without manual masking and with an improved runtime (29.3 s). The GO metric improved the registration accuracy and robustness in the presence of strong image content mismatch. This capability could offer valuable assistance and decision support in spine level localization in a

  17. WE-AB-BRA-01: 3D-2D Image Registration for Target Localization in Spine Surgery: Comparison of Similarity Metrics Against Robustness to Content Mismatch

    Energy Technology Data Exchange (ETDEWEB)

    De Silva, T; Ketcha, M; Siewerdsen, J H [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD (United States); Uneri, A; Reaungamornrat, S [Department of Computer Science, Johns Hopkins University, Baltimore, MD (United States); Vogt, S; Kleinszig, G [Siemens Healthcare XP Division, Erlangen, DE (Germany); Lo, S F; Wolinsky, J P; Gokaslan, Z L [Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, MD (United States); Aygun, N [Department of Raiology and Radiological Sciences, The Johns Hopkins Hospital, Baltimore, MD (United States)

    2015-06-15

    Purpose: In image-guided spine surgery, mapping 3D preoperative images to 2D intraoperative images via 3D-2D registration can provide valuable assistance in target localization. However, the presence of surgical instrumentation, hardware implants, and soft-tissue resection/displacement causes mismatches in image content, confounding existing registration methods. Manual/semi-automatic methods to mask such extraneous content is time consuming, user-dependent, error prone, and disruptive to clinical workflow. We developed and evaluated 2 novel similarity metrics within a robust registration framework to overcome such challenges in target localization. Methods: An IRB-approved retrospective study in 19 spine surgery patients included 19 preoperative 3D CT images and 50 intraoperative mobile radiographs in cervical, thoracic, and lumbar spine regions. A neuroradiologist provided truth definition of vertebral positions in CT and radiography. 3D-2D registration was performed using the CMA-ES optimizer with 4 gradient-based image similarity metrics: (1) gradient information (GI); (2) gradient correlation (GC); (3) a novel variant referred to as gradient orientation (GO); and (4) a second variant referred to as truncated gradient correlation (TGC). Registration accuracy was evaluated in terms of the projection distance error (PDE) of the vertebral levels. Results: Conventional similarity metrics were susceptible to gross registration error and failure modes associated with the presence of surgical instrumentation: for GI, the median PDE and interquartile range was 33.0±43.6 mm; similarly for GC, PDE = 23.0±92.6 mm respectively. The robust metrics GO and TGC, on the other hand, demonstrated major improvement in PDE (7.6 ±9.4 mm and 8.1± 18.1 mm, respectively) and elimination of gross failure modes. Conclusion: The proposed GO and TGC similarity measures improve registration accuracy and robustness to gross failure in the presence of strong image content mismatch. Such

  18. High-performance GPU-based rendering for real-time, rigid 2D/3D-image registration and motion prediction in radiation oncology

    Science.gov (United States)

    Spoerk, Jakob; Gendrin, Christelle; Weber, Christoph; Figl, Michael; Pawiro, Supriyanto Ardjo; Furtado, Hugo; Fabri, Daniella; Bloch, Christoph; Bergmann, Helmar; Gröller, Eduard; Birkfellner, Wolfgang

    2012-01-01

    A common problem in image-guided radiation therapy (IGRT) of lung cancer as well as other malignant diseases is the compensation of periodic and aperiodic motion during dose delivery. Modern systems for image-guided radiation oncology allow for the acquisition of cone-beam computed tomography data in the treatment room as well as the acquisition of planar radiographs during the treatment. A mid-term research goal is the compensation of tumor target volume motion by 2D/3D registration. In 2D/3D registration, spatial information on organ location is derived by an iterative comparison of perspective volume renderings, so-called digitally rendered radiographs (DRR) from computed tomography volume data, and planar reference x-rays. Currently, this rendering process is very time consuming, and real-time registration, which should at least provide data on organ position in less than a second, has not come into existence. We present two GPU-based rendering algorithms which generate a DRR of 512 × 512 pixels size from a CT dataset of 53 MB size at a pace of almost 100 Hz. This rendering rate is feasible by applying a number of algorithmic simplifications which range from alternative volume-driven rendering approaches – namely so-called wobbled splatting – to sub-sampling of the DRR-image by means of specialized raycasting techniques. Furthermore, general purpose graphics processing unit (GPGPU) programming paradigms were consequently utilized. Rendering quality and performance as well as the influence on the quality and performance of the overall registration process were measured and analyzed in detail. The results show that both methods are competitive and pave the way for fast motion compensation by rigid and possibly even non-rigid 2D/3D registration and, beyond that, adaptive filtering of motion models in IGRT. PMID:21782399

  19. Accelerated short-TE 3D proton echo-planar spectroscopic imaging using 2D-SENSE with a 32-channel array coil.

    Science.gov (United States)

    Otazo, Ricardo; Tsai, Shang-Yueh; Lin, Fa-Hsuan; Posse, Stefan

    2007-12-01

    MR spectroscopic imaging (MRSI) with whole brain coverage in clinically feasible acquisition times still remains a major challenge. A combination of MRSI with parallel imaging has shown promise to reduce the long encoding times and 2D acceleration with a large array coil is expected to provide high acceleration capability. In this work a very high-speed method for 3D-MRSI based on the combination of proton echo planar spectroscopic imaging (PEPSI) with regularized 2D-SENSE reconstruction is developed. Regularization was performed by constraining the singular value decomposition of the encoding matrix to reduce the effect of low-value and overlapped coil sensitivities. The effects of spectral heterogeneity and discontinuities in coil sensitivity across the spectroscopic voxels were minimized by unaliasing the point spread function. As a result the contamination from extracranial lipids was reduced 1.6-fold on average compared to standard SENSE. We show that the acquisition of short-TE (15 ms) 3D-PEPSI at 3 T with a 32 x 32 x 8 spatial matrix using a 32-channel array coil can be accelerated 8-fold (R = 4 x 2) along y-z to achieve a minimum acquisition time of 1 min. Maps of the concentrations of N-acetyl-aspartate, creatine, choline, and glutamate were obtained with moderate reduction in spatial-spectral quality. The short acquisition time makes the method suitable for volumetric metabolite mapping in clinical studies.

  20. [Positron emission tomography: diagnostic imaging on a molecular level].

    Science.gov (United States)

    Allemann, K; Wyss, M; Wergin, M; Bley, C Rohrer; Ametamay, S; Bruehlmeier, M; Kaser-Hotz, B

    2004-08-01

    In human medicine positron emission tomography (PET) is a modern diagnostic imaging method. In the present paper we outline the physical principles of PET and give an overview over the main clinic fields where PET is being used, such as neurology, cardiology and oncology. Moreover, we present a current project in veterinary medicine (in collaboration with the Paul Scherrer Institute and the University Hospital Zurich), where a hypoxia tracer is applied to dogs and cats suffering from spontaneous tumors. Finally new developments in the field of PET were discussed.

  1. Simultaneous imaging/reflectivity measurements to assess diagnostic mirror cleaninga)

    Science.gov (United States)

    Skinner, C. H.; Gentile, C. A.; Doerner, R.

    2012-10-01

    Practical methods to clean ITER's diagnostic mirrors and restore reflectivity will be critical to ITER's plasma operations. We describe a technique to assess the efficacy of mirror cleaning techniques and detect any damage to the mirror surface. The method combines microscopic imaging and reflectivity measurements in the red, green, and blue spectral regions and at selected wavelengths. The method has been applied to laser cleaning of single crystal molybdenum mirrors coated with either carbon or beryllium films 150-420 nm thick. It is suitable for hazardous materials such as beryllium as the mirrors remain sealed in a vacuum chamber.

  2. Simultaneous imaging/reflectivity measurements to assess diagnostic mirror cleaning.

    Science.gov (United States)

    Skinner, C H; Gentile, C A; Doerner, R

    2012-10-01

    Practical methods to clean ITER's diagnostic mirrors and restore reflectivity will be critical to ITER's plasma operations. We describe a technique to assess the efficacy of mirror cleaning techniques and detect any damage to the mirror surface. The method combines microscopic imaging and reflectivity measurements in the red, green, and blue spectral regions and at selected wavelengths. The method has been applied to laser cleaning of single crystal molybdenum mirrors coated with either carbon or beryllium films 150-420 nm thick. It is suitable for hazardous materials such as beryllium as the mirrors remain sealed in a vacuum chamber.

  3. 2D-3D shape reconstruction of the distal femur from stereo X-Ray imaging using statistical shape models

    DEFF Research Database (Denmark)

    Baka, N.; Kaptein, B. L.; de Bruijne, Marleen

    2011-01-01

    pose estimation of ground truth shapes as well as 3D shape estimation using a SSM of the whole femur, from stereo cadaver X-rays, in vivo biplane fluoroscopy image-pairs, and an in vivo biplane fluoroscopic sequence. Ground truth shapes for all experiments were available in the form of CT segmentations...

  4. Using Novel 2D Image Manipulation Methods to Aid Initial Concept Generation with Postgraduate Industrial Design Students

    Science.gov (United States)

    Hurn, Karl; Storer, Ian

    2015-01-01

    The aim of this paper is to provide educators and industrial design professionals with an insight into the development of innovative design ideation images manipulation techniques and, highlight how these techniques could be used to not only improve student ideation skills, but also as design enablers for a broader range of professionals working…

  5. Using Novel 2D Image Manipulation Methods to Aid Initial Concept Generation with Postgraduate Industrial Design Students

    Science.gov (United States)

    Hurn, Karl; Storer, Ian

    2015-01-01

    The aim of this paper is to provide educators and industrial design professionals with an insight into the development of innovative design ideation images manipulation techniques and, highlight how these techniques could be used to not only improve student ideation skills, but also as design enablers for a broader range of professionals working…

  6. Imaging of Selenium by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) in 2-D Electrophoresis Gels and Biological Tissues.

    Science.gov (United States)

    Cruz, Elisa Castañeda Santa; Susanne Becker, J; Sabine Becker, J; Sussulini, Alessandra

    2018-01-01

    Selenium and selenoproteins are important components of living organisms that play a role in different biological processes. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful analytical technique that has been employed to obtain distribution maps of selenium in biological tissues in a direct manner, as well as in selenoproteins, previously separated by their molecular masses and isoelectric points using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). In this chapter, we present the protocols to perform LA-ICP-MS imaging experiments, allowing the distribution visualization and determination of selenium and/or selenoproteins in biological systems.

  7. Portal hypertension in patients with cirrhosis: indirect assessment of hepatic venous pressure gradient by measuring azygos flow with 2D-cine phase-contrast magnetic resonance imaging.

    Science.gov (United States)

    Gouya, Hervé; Grabar, Sophie; Vignaux, Olivier; Saade, Anastasia; Pol, Stanislas; Legmann, Paul; Sogni, Philippe

    2016-07-01

    To measure azygos, portal and aortic flow by two-dimensional cine phase-contrast magnetic resonance imaging (2D-cine PC MRI), and to compare the MRI values to hepatic venous pressure gradient (HVPG) measurements, in patients with cirrhosis. Sixty-nine patients with cirrhosis were prospectively included. All patients underwent HVPG measurements, upper gastrointestinal endoscopy and 2D-cine PC MRI measurements of azygos, portal and aortic blood flow. Univariate and multivariate regression analyses were used to evaluate the correlation between the blood flow and HVPG. The performance of 2D-cine PC MRI to diagnose severe portal hypertension (HVPG ≥ 16 mmHg) was determined by receiver operating characteristic curve (ROC) analysis, and area under the curves (AUC) were compared. Azygos and aortic flow values were associated with HVPG in univariate linear regression model. Azygos flow (p cine PC MRI is a promising technique to evaluate significant portal hypertension in patients with cirrhosis. • Noninvasive HVPG assessment can be performed with MRI azygos flow. • Azygos MRI flow is an easy-to-measure marker to detect significant portal hypertension. • MRI flow is more specific that varice grade to detect portal hypertension.

  8. OpenHVSR: imaging the subsurface 2D/3D elastic properties through multiple HVSR modeling and inversion

    Science.gov (United States)

    Bignardi, S.; Mantovani, A.; Abu Zeid, N.

    2016-08-01

    OpenHVSR is a computer program developed in the Matlab environment, designed for the simultaneous modeling and inversion of large Horizontal-to-Vertical Spectral Ratio (HVSR or H/V) datasets in order to construct 2D/3D subsurface models (topography included). The program is designed to provide a high level of interactive experience to the user and still to be of intuitive use. It implements several effective and established tools already present in the code ModelHVSR by Herak (2008), and many novel features such as: -confidence evaluation on lateral heterogeneity -evaluation of frequency dependent single parameter impact on the misfit function -relaxation of Vp/Vs bounds to allow for water table inclusion -a new cost function formulation which include a slope dependent term for fast matching of peaks, which greatly enhances convergence in case of low quality HVSR curves inversion -capability for the user of editing the subsurface model at any time during the inversion and capability to test the changes before acceptance. In what follows, we shall present many features of the program and we shall show its capabilities on both simulated and real data. We aim to supply a powerful tool to the scientific and professional community capable of handling large sets of HSVR curves, to retrieve the most from their microtremor data within a reduced amount of time and allowing the experienced scientist the necessary flexibility to integrate into the model their own geological knowledge of the sites under investigation. This is especially desirable now that microtremor testing has become routinely used. After testing the code over different datasets, both simulated and real, we finally decided to make it available in an open source format. The program is available by contacting the authors.

  9. Optimum image compression rate maintaining diagnostic image quality of digital intraoral radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ju Seop; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology and Institute of Oral Bio Science, School of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    2000-12-15

    The aims of the present study are to determine the optimum compression rate in terms of file size reduction and diagnostic quality of the images after compression and evaluate the transmission speed of original or each compressed images. The material consisted of 24 extracted human premolars and molars. The occlusal surfaces and proximal surfaces of the teeth had a clinical disease spectrum that ranged from sound to varying degrees of fissure discoloration and cavitation. The images from Digora system were exported in TIFF and the images from conventional intraoral film were scanned and digitalized in TIFF by Nikon SF-200 scanner(Nikon, Japan). And six compression factors were chosen and applied on the basis of the results from a pilot study. The total number of images to be assessed were 336. Three radiologists assessed the occlusal and proximal surfaces of the teeth with 5-rank scale. Finally diagnosed as either sound or carious lesion by one expert oral pathologist. And sensitivity and specificity and kappa value for diagnostic agreement was calculated. Also the area (Az) values under the ROC curve were calculated and paired t-test and oneway ANOVA test was performed. Thereafter, transmission time of the image files of the each compression level were compared with that of the original image files. No significant difference was found between original and the corresponding images up to 7% (1:14) compression ratio for both the occlusal and proximal caries (p<0.05). JPEG3 (1:14) image files are transmitted fast more than 10 times, maintained diagnostic information in image, compared with original image files. 1:14 compressed image file may be used instead of the original image and reduce storage needs and transmission time.

  10. Multiphoton microscopy as a diagnostic imaging modality for lung cancer

    Science.gov (United States)

    Pavlova, Ina; Hume, Kelly R.; Yazinski, Stephanie A.; Peters, Rachel M.; Weiss, Robert S.; Webb, Watt W.

    2010-02-01

    Lung cancer is the leading killer among all cancers for both men and women in the US, and is associated with one of the lowest 5-year survival rates. Current diagnostic techniques, such as histopathological assessment of tissue obtained by computed tomography guided biopsies, have limited accuracy, especially for small lesions. Early diagnosis of lung cancer can be improved by introducing a real-time, optical guidance method based on the in vivo application of multiphoton microscopy (MPM). In particular, we hypothesize that MPM imaging of living lung tissue based on twophoton excited intrinsic fluorescence and second harmonic generation can provide sufficient morphologic and spectroscopic information to distinguish between normal and diseased lung tissue. Here, we used an experimental approach based on MPM with multichannel fluorescence detection for initial discovery that MPM spectral imaging could differentiate between normal and neoplastic lung in ex vivo samples from a murine model of lung cancer. Current results indicate that MPM imaging can directly distinguish normal and neoplastic lung tissues based on their distinct morphologies and fluorescence emission properties in non-processed lung tissue. Moreover, we found initial indication that MPM imaging differentiates between normal alveolar tissue, inflammatory foci, and lung neoplasms. Our long-term goal is to apply results from ex vivo lung specimens to aid in the development of multiphoton endoscopy for in vivo imaging of lung abnormalities in various animal models, and ultimately for the diagnosis of human lung cancer.

  11. Assessing the value of diagnostic imaging: the role of perception

    Science.gov (United States)

    Potchen, E. J.; Cooper, Thomas G.

    2000-04-01

    The value of diagnostic radiology rests in its ability to provide information. Information is defined as a reduction in randomness. Quality improvement in any system requires diminution in the variation in its performance. The major variation in performance of the system of diagnostic radiology occurs in observer performance and in the communication of information from the observer to someone who will apply that information to the benefit of the patient. The ability to provide information can be determined by observer performance studies using a receiver-operating characteristic (ROC) curve analysis. The amount of information provided by each observer can be measured in terms of the uncertainty they reduce. Using a set of standardized radiographs, some normal and some abnormal, sorting them randomly, and then asking an observer to redistribute them according to their probability of normality can measure the difference in the value added by different observers. By applying this observer performance measure, we have been able to characterize individual radiologists, groups of radiologists, and regions of the United States in their ability to add value in chest radiology. The use of these technologies in health care may improve upon the contribution of diagnostic imaging.

  12. A high-frequency transimpedance amplifier for CMOS integrated 2D CMUT array towards 3D ultrasound imaging.

    Science.gov (United States)

    Huang, Xiwei; Cheong, Jia Hao; Cha, Hyouk-Kyu; Yu, Hongbin; Je, Minkyu; Yu, Hao

    2013-01-01

    One transimpedance amplifier based CMOS analog front-end (AFE) receiver is integrated with capacitive micromachined ultrasound transducers (CMUTs) towards high frequency 3D ultrasound imaging. Considering device specifications from CMUTs, the TIA is designed to amplify received signals from 17.5MHz to 52.5MHz with center frequency at 35MHz; and is fabricated in Global Foundry 0.18-µm 30-V high-voltage (HV) Bipolar/CMOS/DMOS (BCD) process. The measurement results show that the TIA with power-supply 6V can reach transimpedance gain of 61dBΩ and operating frequency from 17.5MHz to 100MHz. The measured input referred noise is 27.5pA/√Hz. Acoustic pulse-echo testing is conducted to demonstrate the receiving functionality of the designed 3D ultrasound imaging system.

  13. Fully automatic left ventricular myocardial strain estimation in 2D short-axis tagged magnetic resonance imaging

    Science.gov (United States)

    Morais, Pedro; Queirós, Sandro; Heyde, Brecht; Engvall, Jan; 'hooge, Jan D.; Vilaça, João L.

    2017-09-01

    Cardiovascular diseases are among the leading causes of death and frequently result in local myocardial dysfunction. Among the numerous imaging modalities available to detect these dysfunctional regions, cardiac deformation imaging through tagged magnetic resonance imaging (t-MRI) has been an attractive approach. Nevertheless, fully automatic analysis of these data sets is still challenging. In this work, we present a fully automatic framework to estimate left ventricular myocardial deformation from t-MRI. This strategy performs automatic myocardial segmentation based on B-spline explicit active surfaces, which are initialized using an annular model. A non-rigid image-registration technique is then used to assess myocardial deformation. Three experiments were set up to validate the proposed framework using a clinical database of 75 patients. First, automatic segmentation accuracy was evaluated by comparing against manual delineations at one specific cardiac phase. The proposed solution showed an average perpendicular distance error of 2.35  ±  1.21 mm and 2.27  ±  1.02 mm for the endo- and epicardium, respectively. Second, starting from either manual or automatic segmentation, myocardial tracking was performed and the resulting strain curves were compared. It is shown that the automatic segmentation adds negligible differences during the strain-estimation stage, corroborating its accuracy. Finally, segmental strain was compared with scar tissue extent determined by delay-enhanced MRI. The results proved that both strain components were able to distinguish between normal and infarct regions. Overall, the proposed framework was shown to be accurate, robust, and attractive for clinical practice, as it overcomes several limitations of a manual analysis.

  14. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    Energy Technology Data Exchange (ETDEWEB)

    Kurebayashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Sakurai, H., E-mail: sakurail@sci.kj.yamagata-u.ac.jp [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Takahashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Doshita, N. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kikuchi, S. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Tokanai, F. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Horiuchi, K. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Tajima, Y. [Institute of Arts and Sciences, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Oe, T. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sato, T. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Gunji, S. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Inui, E. [Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kondo, K. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Iwata, N. [Dept. of Earth and Environmental Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sasaki, N. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Matsuzaki, H. [Micro Analysis Laboratory, Tandem accelerator (MALT), The University Museum, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Kunieda, S. [Nuclear Data Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun 319-1195, Ibaraki (Japan)

    2015-11-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10{sup –9} PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×10{sup 13} was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al.

  15. The Segmentation of FMI Image Based on 2-D Dyadic Wavelet Transform%基于二维小波变换的FMI图象分割

    Institute of Scientific and Technical Information of China (English)

    刘瑞林; 仵岳奇; 柳建华; 马勇

    2005-01-01

    A key aspect in extracting quantitative information from FMI logs is to segment the FMI image to get images of pores, vugs and fractures. A segmentation method based on the dyadic wavelet transform in 2-D is introduced in this paper. The first step is to find all the edge pixels of the FMI image using the 2-D wavelet transform. The second step is to calculate a segmentation threshold based on the average value of the edge pixels. Field data processing examples show that sub-images of vugs and fractures can be correctly separated from original FMI data continuously and automatically along the depth axis. The image segmentation lays the foundation for in-situ parameter calculation.%为了从FMI资料中定量提取参数,一个重要的步骤是从实际FMI资料中分离出反映溶孔、溶洞、裂缝的子图像.本文给出的方法,考虑图像像元邻域的特征,应用二维小波变换求出目标与背景边缘的点集,按这个边缘点集的坐标点所对应的原图像像素灰度值的平均值作为分割阈值进行图像分割.实际资料处理表明,应用这种方法可以从实际的FMI资料中准确地分割出孔洞、裂缝的子图像并且可以按深度段连续自动处理,为后续定量计算参数奠定了良好基础.

  16. Meeting the Needs for Radiation Protection: Diagnostic Imaging.

    Science.gov (United States)

    Frush, Donald P

    2017-02-01

    Radiation and potential risk during medical imaging is one of the foremost issues for the imaging community. Because of this, there are growing demands for accountability, including appropriate use of ionizing radiation in diagnostic and image-guided procedures. Factors contributing to this include increasing use of medical imaging; increased scrutiny (from awareness to alarm) by patients/caregivers and the public over radiation risk; and mounting calls for accountability from regulatory, accrediting, healthcare coverage (e.g., Centers for Medicare and Medicaid Services), and advisory agencies and organizations as well as industry (e.g., NEMA XR-29, Standard Attributes on CT Equipment Related to Dose Optimization and Management). Current challenges include debates over uncertainty with risks with low-level radiation; lack of fully developed and targeted products for diagnostic imaging and radiation dose monitoring; lack of resources for and clarity surrounding dose monitoring programs; inconsistencies across and between practices for design, implementation and audit of dose monitoring programs; lack of interdisciplinary programs for radiation protection of patients; potential shortages in personnel for these and other consensus efforts; and training concerns as well as inconsistencies for competencies throughout medical providers' careers for radiation protection of patients. Medical care providers are currently in a purgatory between quality- and value-based imaging paradigms, a state that has yet to mature to reward this move to quality-based performance. There are also deficits in radiation expertise personnel in medicine. For example, health physics academic programs and graduates have recently declined, and medical physics residency openings are currently at a third of the number of graduates. However, leveraging solutions to the medical needs will require money and resources, beyond personnel alone. Energy and capital will need to be directed to

  17. Magnetic nanoparticles in magnetic resonance imaging and diagnostics.

    Science.gov (United States)

    Rümenapp, Christine; Gleich, Bernhard; Haase, Axel

    2012-05-01

    Magnetic nanoparticles are useful as contrast agents for magnetic resonance imaging (MRI). Paramagnetic contrast agents have been used for a long time, but more recently superparamagnetic iron oxide nanoparticles (SPIOs) have been discovered to influence MRI contrast as well. In contrast to paramagnetic contrast agents, SPIOs can be functionalized and size-tailored in order to adapt to various kinds of soft tissues. Although both types of contrast agents have a inducible magnetization, their mechanisms of influence on spin-spin and spin-lattice relaxation of protons are different. A special emphasis on the basic magnetism of nanoparticles and their structures as well as on the principle of nuclear magnetic resonance is made. Examples of different contrast-enhanced magnetic resonance images are given. The potential use of magnetic nanoparticles as diagnostic tracers is explored. Additionally, SPIOs can be used in diagnostic magnetic resonance, since the spin relaxation time of water protons differs, whether magnetic nanoparticles are bound to a target or not.

  18. Infrared absorption imaging of 2D supersonic jet expansions: Free expansion, cluster formation, and shock wave patterns.

    Science.gov (United States)

    Zischang, Julia; Suhm, Martin A

    2013-07-14

    N2O/He gas mixtures are expanded through a 10 × 0.5 mm(2) slit nozzle and imaged by direct absorption vibrational spectroscopy, employing a HgCdTe focal plane array detector after interferometric modulation. N2O cluster formation in the free supersonic expansion is visualized. The expansion structure behind the frontal shock is investigated as a function of background pressure. At high pressures, a sequence of stationary density peaks along a narrow directed flow channel is characterized. The potential of the technique for the elucidation of aggregation mechanisms is emphasized.

  19. 2D/3D cryo x-ray fluorescence imaging at the bionanoprobe at the advanced photon source

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S., E-mail: sichen@aps.anl.gov; Vine, D. J.; Lai, B. [Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439 (United States); Paunesku, T.; Yuan, Y.; Woloschak, G. E. [Department of Radiation Oncology, Northwester University, Chicago, IL 60611 (United States); Deng, J. [Applied Physics, Northwestern University, Evanston, IL 60208 (United States); Jin, Q.; Hong, Y. P. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Flachenecker, C.; Hornberger, B. [Carl Zeiss X-ray Microscopy, Pleasanton, CA 94588 (United States); Brister, K. [Synchrotron Research Center, Northwestern University, Argonne, IL 60439 (United States); Jacobsen, C. [Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439 (United States); Applied Physics, Northwestern University, Evanston, IL 60208 (United States); Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Vogt, S. [Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439 (United States); Department of Radiation Oncology, Northwester University, Chicago, IL 60611 (United States)

    2016-01-28

    Trace elements, particularly metals, play very important roles in biological systems. Synchrotron-based hard X-ray fluorescence microscopy offers the most suitable capabilities to quantitatively study trace metals in thick biological samples, such as whole cells and tissues. In this manuscript, we have demonstrated X-ray fluorescence imaging of frozen-hydrated whole cells using the recent developed Bionanoprobe (BNP). The BNP provides spatial resolution down to 30 nm and cryogenic capabilities. Frozen-hydrated biological cells have been directly examined on a sub-cellular level at liquid nitrogen temperatures with minimal sample preparation.

  20. 2D and 3D high resolution seismic imaging of shallow Solfatara crater in Campi Flegrei (Italy): new insights on deep hydrothermal fluid circulation processes

    Science.gov (United States)

    De Landro, Grazia; Gammaldi, Sergio; Serlenga, Vincenzo; Amoroso, Ortensia; Russo, Guido; Festa, Gaetano; D'Auria, Luca; Bruno, Pier Paolo; Gresse, Marceau; Vandemeulebrouck, Jean; Zollo, Aldo

    2017-04-01

    Seismic tomography can be used to image the spatial variation of rock properties within complex geological media such as volcanoes. Solfatara is a volcano located within the Campi Flegrei still active caldera, characterized by periodic episodes of extended, low-rate ground subsidence and uplift called bradyseism accompanied by intense seismic and geochemical activities. In particular, Solfatara is characterized by an impressive magnitude diffuse degassing, which underlines the relevance of fluid and heat transport at the crater and prompted further research to improve the understanding of the hydrothermal system feeding the surface phenomenon. In this line, an active seismic experiment, Repeated Induced Earthquake and Noise (RICEN) (EU Project MEDSUV), was carried out between September 2013 and November 2014 to provide time-varying high-resolution images of the structure of Solfatara. In this study we used the datasets provided by two different acquisition geometries: a) A 2D array cover an area of 90 x 115 m ^ 2 sampled by a regular grid of 240 vertical sensors deployed at the crater surface; b) two 1D orthogonal seismic arrays deployed along NE-SW and NW-SE directions crossing the 400 m crater surface. The arrays are sampled with a regular line of 240 receiver and 116 shots. We present 2D and 3D tomographic high-resolution P-wave velocity images obtained using two different tomographic methods adopting a multiscale strategy. The 3D image of the shallow (30-35 m) central part of Solfatara crater is performed through the iterative, linearized, tomographic inversion of the P-wave first arrival times. 2D P-wave velocity sections (60-70 m) are obtained using a non-linear travel-time tomography method based on the evaluation of a posteriori probability density with a Bayesian approach. The 3D retrieved images integrated with resistivity section and temperature and CO2 flux measurements , define the following characteristics: 1. A depth dependent P-wave velocity layer

  1. PixFEL: developing a fine pitch, fast 2D X-ray imager for the next generation X-FELs

    Science.gov (United States)

    Ratti, L.; Comotti, D.; Fabris, L.; Grassi, M.; Lodola, L.; Malcovati, P.; Manghisoni, M.; Re, V.; Traversi, G.; Vacchi, C.; Bettarini, S.; Casarosa, G.; Forti, F.; Morsani, F.; Paladino, A.; Paoloni, E.; Rizzo, G.; Benkechkache, M. A.; Dalla Betta, G.-F.; Mendicino, R.; Pancheri, L.; Verzellesi, G.; Xu, H.

    2015-10-01

    The PixFEL project is conceived as the first stage of a long term research program aiming at the development of advanced X-ray imaging instrumentation for applications at the free electron laser (FEL) facilities. The project aims at substantially advancing the state-of-the-art in the field of 2D X-ray imaging by exploring cutting-edge solutions for sensor development, for integration processes and for readout channel architectures. The main focus is on the development of the fundamental microelectronic building blocks for detector readout and on the technologies for the assembly of a multilayer module with minimum dead area. This work serves the purpose of introducing the main features of the project, together with the simulation results leading to the first prototyping run.

  2. 2D substrate imaging of a tapered laser cavity based on InGaAs quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Pagano, R; O' Callaghan, J; Mukherjee, J; Mclnerney, J G; Corbett, B [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland); Reithmaier, J P [Technische Physik Institute of Nanostructure Technologies and Analytics (INA) University of Kassel (Germany); Deubert, S; Forchel, A, E-mail: roberto.pagano@tyndall.i [Technische Physik, University of Wuerzburg, 97074 Wuerzburg (Germany)

    2009-11-15

    Tapered cavities are an excellent solution to obtaining high brightness semiconductor laser sources for use in applications from frequency doubling to material processing. The high power density levels reached in such lasers can lead to nonlinear mechanisms related to the refractive index variations that de-stabilise the optical field distribution inside the laser cavity. These mechanisms are detrimental to the beam quality of the laser limiting its focussing ability. In this work we map the spatial distribution and evolution of the carrier density in tapered lasers as a function of injection current. A device with a taper length of 2.75 mm, taper angle of 6{sup 0} and ridge length of 1.25 mm is used to demonstrate the principle. The active region consists of three layers of InGaAs quantum dots emitting around 950 nm. A window for imaging the spontaneous emission profile through the transparent GaAs substrate was formed by patterning the n-contact metal layer. The imaging was performed in the continuous wave regime to include the thermal-induced refractive index perturbation. The results show a non-uniform carrier and thermal distribution inside the cavity even at low current levels.

  3. Image processing methods and architectures in diagnostic pathology.

    Directory of Open Access Journals (Sweden)

    Oscar DĂŠniz

    2010-05-01

    Full Text Available Grid technology has enabled the clustering and the efficient and secure access to and interaction among a wide variety of geographically distributed resources such as: supercomputers, storage systems, data sources, instruments and special devices and services. Their main applications include large-scale computational and data intensive problems in science and engineering. General grid structures and methodologies for both software and hardware in image analysis for virtual tissue-based diagnosis has been considered in this paper. This methods are focus on the user level middleware. The article describes the distributed programming system developed by the authors for virtual slide analysis in diagnostic pathology. The system supports different image analysis operations commonly done in anatomical pathology and it takes into account secured aspects and specialized infrastructures with high level services designed to meet application requirements. Grids are likely to have a deep impact on health related applications, and therefore they seem to be suitable for tissue-based diagnosis too. The implemented system is a joint application that mixes both Web and Grid Service Architecture around a distributed architecture for image processing. It has shown to be a successful solution to analyze a big and heterogeneous group of histological images under architecture of massively parallel processors using message passing and non-shared memory.

  4. Thermoacoustic imaging and spectroscopy for enhanced cancer diagnostics

    Science.gov (United States)

    Bauer, Daniel Ryan

    Early detection of cancer is paramount for improved patient survival. This dissertation presents work developing imaging techniques to improve cancer diagnostics and detection utilizing light and microwave induced thermoacoustic imaging. In the second chapter, the well-established pre-clinical mouse window chamber model is interfaced with simultaneously acquired high-resolution pulse echo (PE) ultrasound and photoacoustic (PA) imaging. Co-registered PE and PA imaging, coupled with developed image segmentation algorithms, are used to quantitatively track and monitor the size, shape, heterogeneity, and neovasculature of the tumor microenvironment during a month long study. Average volumetric growth was 5.35 mm3/day, which correlated well with two dimensional results from fluorescent imaging (R = 0.97, p imaging is also employed to probe the assumed oxygenation status of the tumor vasculature. The window chamber model combined with high-resolution PE and PA imaging could form a powerful testbed for characterizing cancers and evaluating new contrast and therapeutic agents. The third chapter utilizes a clinical ultrasound array to facilitate fast volumetric spectroscopic PA imaging to detect and discriminate endogenous absorbers (i.e. oxy/deoxygenated hemoglobin) as well as exogenous PA contrast agents (i.e. gold nanorods, fluorophores). In vivo spatiotemporal tracking of administered gold nanorods is presented, with the contrast agent augmenting the PA signal 18 dB. Furthermore, through the use of spectral unmixing algorithms, the relative concentrations of multiple endogenous and exogenous co-localized absorbers were reconstructed in tumor bearing mice. The concentration of Alexaflour647 was calculated to increase nearly 20 dB in the center of a prostate tumor after a tail-vein injection of the contrast agent. Additionally, after direct subcutaneous injections of two different gold nanorods into a breast tumor, the concentration of each nanoparticle was discriminated

  5. 1D and 2D diffusion pore imaging on a preclinical MR system using adaptive rephasing: Feasibility and pulse sequence comparison

    Science.gov (United States)

    Bertleff, Marco; Domsch, Sebastian; Laun, Frederik B.; Kuder, Tristan A.; Schad, Lothar R.

    2017-05-01

    Diffusion pore imaging (DPI) has recently been proposed as a means to acquire images of the average pore shape in an image voxel or region of interest. The highly asymmetric gradient scheme of its sequence makes it substantially demanding in terms of the hardware of the NMR system. The aim of this work is to show the feasibility of DPI on a preclinical 9.4 T animal scanner. Using water-filled capillaries with an inner radius of 10 μm, four different variants of the DPI sequence were compared in 1D and 2D measurements. The pulse sequences applied cover the basic implementation using one long and one temporally narrow gradient pulse, a CPMG-like variant with multiple refocusing RF pulses as well as two variants splitting up the long gradient and distributing it on either side of the refocusing pulse. Substantial differences between the methods were found in terms of signal-to-noise ratio, contrast, blurring, deviations from the expected results and sensitivity to gradient imperfections. Each of the tested sequences was found to produce characteristic gradient mismatches dependent on the absolute value, direction and sign of the applied q-value. Read gradients were applied to compensate these mismatches translating them into time shifts, which enabled 1D DPI yielding capillary radius estimations within the tolerances specified by the manufacturer. For a successful DPI application in 2D, a novel gradient amplitude adaption scheme was implemented to correct for the occurring time shifts. Using this adaption, higher conformity to the expected pore shape, reduced blurring and enhanced contrast were achieved. Images of the phantom's pore shape could be acquired with a nominal resolution of 2.2 μm.

  6. Diagnostic imaging of psoriatic arthritis. Part II: magnetic resonance imaging and ultrasonography.

    Science.gov (United States)

    Sudoł-Szopińska, Iwona; Pracoń, Grzegorz

    2016-06-01

    Plain radiography reveals specific, yet late changes of advanced psoriatic arthritis. Early inflammatory changes are seen both on magnetic resonance imaging and ultrasound within peripheral joints (arthritis, synovitis), tendons sheaths (tenosynovitis, tendovaginitis) and entheses (enthesitis, enthesopathy). In addition, magnetic resonance imaging enables the assessment of inflammatory features in the sacroiliac joints (sacroiliitis), and the spine (spondylitis). In this article, we review current opinions on the diagnostics of some selective, and distinctive features of psoriatic arthritis concerning magnetic resonance imaging and ultrasound and present some hypotheses on psoriatic arthritis etiopathogenesis, which have been studied with the use of magnetic resonance imaging. The following elements of the psoriatic arthritis are discussed: enthesitis, extracapsular inflammation, dactylitis, distal interphalangeal joint and nail disease, and the ability of magnetic resonance imaging to differentiate undifferentiated arthritis, the value of whole-body magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging.

  7. Diagnostic imaging of psoriatic arthritis. Part II: magnetic resonance imaging and ultrasonography

    Directory of Open Access Journals (Sweden)

    Iwona Sudoł-Szopińska

    2016-06-01

    Full Text Available Plain radiography reveals specific, yet late changes of advanced psoriatic arthritis. Early inflammatory changes are seen both on magnetic resonance imaging and ultrasound within peripheral joints (arthritis, synovitis, tendons sheaths (tenosynovitis, tendovaginitis and entheses (enthesitis, enthesopathy. In addition, magnetic resonance imaging enables the assessment of inflammatory features in the sacroiliac joints (sacroiliitis, and the spine (spondylitis. In this article, we review current opinions on the diagnostics of some selective, and distinctive features of psoriatic arthritis concerning magnetic resonance imaging and ultrasound and present some hypotheses on psoriatic arthritis etiopathogenesis, which have been studied with the use of magnetic resonance imaging. The following elements of the psoriatic arthritis are discussed: enthesitis, extracapsular inflammation, dactylitis, distal interphalangeal joint and nail disease, and the ability of magnetic resonance imaging to differentiate undifferentiated arthritis, the value of whole-body magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging.

  8. 3-D Ultrasound Imaging Performance of a Row-Column Addressed 2-D Array Transducer: A Measurement Study

    DEFF Research Database (Denmark)

    Rasmussen, Morten Fischer; Jensen, Jørgen Arendt

    2013-01-01

    A real-time 3-D ultrasound measurement using only 32 elements and 32 emissions is presented. The imaging quality is compared to a conventionally fully addressed array using 1024 elements and 256 emissions. The main-lobe of the measured line spread function is almost identical, but the side-lobe l...... ultrasound probe made by Vermon S.A....... is 510% larger than when row-column addressing the array. The cyst radius needed to achieve -20 dB intensity in the cyst is 396% larger for the fully addressed array compared to the row-column addressed array. The measurements were made using the experimental ultrasound scanner SARUS and a 32x32 element...

  9. Diffusion-weighted MRI of the Prostate: Advantages of Zoomed EPI with Parallel-transmit-accelerated 2D-selective Excitation Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Thierfelder, Kolja M.; Scherr, Michael K.; Weiss, Jakob; Mueller-Lisse, Ullrich G.; Theisen, Daniel [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Notohamiprodjo, Mike; Nikolaou, Konstantin [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); University Hospital Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Dietrich, Olaf [Ludwig-Maximilians-University Hospital Munich, Josef Lissner Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Munich (Germany); Pfeuffer, Josef [Siemens Healthcare, Application Development, Erlangen (Germany)

    2014-12-15

    The purpose of our study was to evaluate the use of 2D-selective, parallel-transmit excitation magnetic resonance imaging (MRI) for diffusion-weighted echo-planar imaging (pTX-EPI) of the prostate, and to compare it to conventional, single-shot EPI (c-EPI). The MRI examinations of 35 patients were evaluated in this prospective study. PTX-EPI was performed with a TX-acceleration factor of 1.7 and a field of view (FOV) of 150 x 90 mm{sup 2}, whereas c-EPI used a full FOV of 380 x 297 mm{sup 2}. Two readers evaluated three different aspects of image quality on 5-point Likert scales. To quantify distortion artefacts, maximum diameters and prostate volume were determined for both techniques and compared to T2-weighted imaging. The zoomed pTX-EPI was superior to c-EPI with respect to overall image quality (3.39 ± 0.62 vs 2.45 ± 0.67) and anatomic differentiability (3.29 ± 0.65 vs 2.41 ± 0.65), each with p < 0.0001. Artefacts were significantly less severe in pTX-EPI (0.93 ± 0.73 vs 1.49 ± 1.08), p < 0.001. The quantitative analysis yielded a higher agreement of pTX-EPI with T2-weighted imaging than c-EPI with respect to coronal (ICCs: 0.95 vs 0.93) and sagittal (0.86 vs 0.73) diameters as well as prostate volume (0.94 vs 0.92). Apparent diffusion coefficient (ADC) values did not differ significantly between the two techniques (p > 0.05). Zoomed pTX-EPI leads to substantial improvements in diffusion-weighted imaging (DWI) of the prostate with respect to different aspects of image quality and severity of artefacts. (orig.)

  10. Use of Caval Subtraction 2D Phase-Contrast MR Imaging to Measure Total Liver and Hepatic Arterial Blood Flow: Preclinical Validation and Initial Clinical Translation.

    Science.gov (United States)

    Chouhan, Manil D; Mookerjee, Rajeshwar P; Bainbridge, Alan; Walker-Samuel, Simon; Davies, Nathan; Halligan, Steve; Lythgoe, Mark F; Taylor, Stuart A

    2016-09-01

    Purpose To validate caval subtraction two-dimensional (2D) phase-contrast magnetic resonance (MR) imaging measurements of total liver blood flow (TLBF) and hepatic arterial fraction in an animal model and evaluate consistency and reproducibility in humans. Materials and Methods Approval from the institutional ethical committee for animal care and research ethics was obtained. Fifteen Sprague-Dawley rats underwent 2D phase-contrast MR imaging of the portal vein (PV) and infrahepatic and suprahepatic inferior vena cava (IVC). TLBF and hepatic arterial flow were estimated by subtracting infrahepatic from suprahepatic IVC flow and PV flow from estimated TLBF, respectively. Direct PV transit-time ultrasonography (US) and fluorescent microsphere measurements of hepatic arterial fraction were the standards of reference. Thereafter, consistency of caval subtraction phase-contrast MR imaging-derived TLBF and hepatic arterial flow was assessed in 13 volunteers (mean age, 28.3 years ± 1.4) against directly measured phase-contrast MR imaging PV and proper hepatic arterial inflow; reproducibility was measured after 7 days. Bland-Altman analysis of agreement and coefficient of variation comparisons were undertaken. Results There was good agreement between PV flow measured with phase-contrast MR imaging and that measured with transit-time US (mean difference, -3.5 mL/min/100 g; 95% limits of agreement [LOA], ±61.3 mL/min/100 g). Hepatic arterial fraction obtained with caval subtraction agreed well with those with fluorescent microspheres (mean difference, 4.2%; 95% LOA, ±20.5%). Good consistency was demonstrated between TLBF in humans measured with caval subtraction and direct inflow phase-contrast MR imaging (mean difference, -1.3 mL/min/100 g; 95% LOA, ±23.1 mL/min/100 g). TLBF reproducibility at 7 days was similar between the two methods (95% LOA, ±31.6 mL/min/100 g vs ±29.6 mL/min/100 g). Conclusion Caval subtraction phase-contrast MR imaging is a simple and clinically

  11. A 2D panoramic surgical stent imaging: Complete arch mandibular implant fixed prosthesis along with bar supported maxillary over denture

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Singhal

    2017-01-01

    Full Text Available Successful rehabilitation of a patient should restore function, esthetic, and speech by prosthesis. Treatment modalities vary from patient to patient. Semi-precision attachments and implants offer several advantages over the traditional approach. The aim and objective of this report was to assess a case of a 55-year-old female patient who had lost all her teeth, except maxillary canines #13 and #23 and with severe bone loss in the mandible. Tooth-supported bar attachment was planned for maxilla, and a total of five dental implants were placed in the mandible using a flapless approach aided by radiographic gutta-percha surgical stents over panoramic two-dimensional imaging. Customized, radiographic stents help for the placement of implant in the view of paralleling and flapless surgery, completely. An immediate loading protocol is adopted as from day of the surgery to 6 weeks along with implant supported full arch fixed dentures after 4 months. The outcome of the treatment was impressive, and the patient gave a positive response with superb esthetics and functions.

  12. Implications of respiratory motion for the quantification of 2D MR spectroscopic imaging data in the abdomen

    Science.gov (United States)

    Schwarz, A. J.; Leach, M. O.

    2000-08-01

    Magnetic resonance spectroscopic imaging (MRSI) studies in the abdomen or breast are acquired in the presence of respiratory motion. This modifies the point spread function (PSF) and hence the reconstructed spectra. We evaluated the quantitative effects of both periodic and aperiodic motion on spectra localized by MRSI. Artefactual signal changes, both the modification of native to a voxel and spurious signals arising elsewhere, depend primarily upon the motion amplitude relative to the voxel dimension. A similar dependence on motion amplitude was observed for simple harmonic motion (SHM), quasi-periodic motion and random displacements. No systematic dependence upon the period or initial phase of SHM or on the array size was found. There was also no significant variation with motion direction relative to the internal and external phase-encoding directions. In measured excursion ranges of 20 breast and abdominal tumours, 70% moved ≤ 5 mm, while 30% moved 6-23 mm. The diaphragm and fatty tissues in the gut typically moved ~ 15-20 mm. While tumour/organ excursions less than half the voxel dimension do not substantially affect native signals, the bleeding in of strong lipid signals will be problematic in 1H studies. MRSI studies in the abdomen, even of relatively well-anchored tumours, are thus likely to benefit from the addition of respiratory triggering or other motion compensation strategies.

  13. Comparison between 2D ultrasonography and magnetic resonance imaging for assessing brain and spine parameters in fetuses with spina bifida.

    Science.gov (United States)

    Araujo Júnior, Edward; Nakano, Mayra Lemos; Nardozza, Luciano Marcondes Machado; Haratz, Karina Krajden; Oliveira, Patrícia Soares; Martins, Wellington P; Ajzen, Sérgio Aron; Moron, Antonio Fernandes

    2013-05-01

    To compare two-dimensional ultrasonography (2DUS) and magnetic resonance imaging (MRI) for assessing brain and spine parameters in fetuses with spina bifida. A cross-sectional study was conducted on 15 fetuses with spina bifida (one with encephalocele, four with rachischisis and 10 with myelomeningocele). The size of the atrium of the lateral ventricle, percentage shortening of the cerebellum, degree of compromising of the first vertebra and total number of vertebras affected by herniation were assessed. The MRI examination was performed not more than 7 days after the 2DUS. To compare and correlate the parameters from the two techniques, the paired Student's t test and intraclass correlation coefficient (ICC) were used. To assess the correlations of atrium measurements from 2DUS and MRI with other parameters, Pearson's correlation coefficient (r) was used. No significant difference was observed in any of the means of the parameters assessed using the two techniques (p > 0.05). Both 2DUS and MRI seemed to present satisfactory reliability in measurements on the size of the atrium of the lateral ventricle and the first vertebra affected (ICC = 0.88 and 0.75, respectively). Measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters than did measurements from MRI. In fetuses with spina bifida, 2DUS and MRI present similar results, but measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters.

  14. Fast and robust 2D-shape extraction using discrete-point sampling and centerline grouping in complex images.

    Science.gov (United States)

    Zhu, Zongxiao; Wang, Guoyou; Liu, Jianguo; Chen, Zhong

    2013-12-01

    This paper initially develops the discrete-point sampling operator's concept, model, and parameters that we have previously proposed, and makes its belt-shaped regions in a discrete-point sampling map more salient and appropriate for centerline extraction. The cross-sectional features of these belt-shaped regions are then analyzed and seven types of feature points are defined to facilitate descriptions of such features. Based on these feature points, a three-level detection system is proposed, including feature points, line segments, and centerlines, to extract centerlines from the belt-shaped regions. Eight basic types of centerlines and five types of relationships among the centerlines are defined by computational geometry algorithms, and Gestalt laws are used to cluster them into groupings. If some prior information about a desired shape is available, retrieval grouping may be carried out by a discrete-point sampling map, the purpose of which is to find centerlines by best matching with prior information. Discrete-point sampling effectually overcomes the influences of interference from noise, textures, and uneven illumination, and greatly reduces the difficulty of centerline extraction. Centerline clustered groupings and retrieval grouping can offer a strong anti-interference ability with nonlinear deformations such as articulation and occlusion. This method can extract large-scale complex shapes combined of lines and planes from complex images. The wheel location results of noise test and other shape extraction experiments show that our method has a strong capability to persist with nonlinear deformations.

  15. Gold Nanoconstructs for Multimodal Diagnostic Imaging and Photothermal Cancer Therapy

    Science.gov (United States)

    Coughlin, Andrew James

    Cancer accounts for nearly 1 out of every 4 deaths in the United States, and because conventional treatments are limited by morbidity and off-target toxicities, improvements in cancer management are needed. This thesis further develops nanoparticle-assisted photothermal therapy (NAPT) as a viable treatment option for cancer patients. NAPT enables localized ablation of disease because heat generation only occurs where tissue permissive near-infrared (NIR) light and absorbing nanoparticles are combined, leaving surrounding normal tissue unharmed. Two principle approaches were investigated to improve the specificity of this technique: multimodal imaging and molecular targeting. Multimodal imaging affords the ability to guide NIR laser application for site-specific NAPT and more holistic characterization of disease by combining the advantages of several diagnostic technologies. Towards the goal of image-guided NAPT, gadolinium-conjugated gold-silica nanoshells were engineered and demonstrated to enhance imaging contrast across a range of diagnostic modes, including T1-weighted magnetic resonance imaging, X-Ray, optical coherence tomography, reflective confocal microscopy, and two-photon luminescence in vitro as well as within an animal tumor model. Additionally, the nanoparticle conjugates were shown to effectively convert NIR light to heat for applications in photothermal therapy. Therefore, the broad utility of gadolinium-nanoshells for anatomic localization of tissue lesions, molecular characterization of malignancy, and mediators of ablation was established. Molecular targeting strategies may also improve NAPT by promoting nanoparticle uptake and retention within tumors and enhancing specificity when malignant and normal tissue interdigitate. Here, ephrinA1 protein ligands were conjugated to nanoshell surfaces for particle homing to overexpressed EphA2 receptors on prostate cancer cells. In vitro, successful targeting and subsequent photothermal ablation of

  16. Spatially selective 2D RF inner field of view (iFOV diffusion kurtosis imaging (DKI of the pediatric spinal cord

    Directory of Open Access Journals (Sweden)

    Chris J. Conklin

    2016-01-01

    Full Text Available Magnetic resonance based diffusion imaging has been gaining more utility and clinical relevance over the past decade. Using conventional echo planar techniques, it is possible to acquire and characterize water diffusion within the central nervous system (CNS; namely in the form of Diffusion Weighted Imaging (DWI and Diffusion Tensor Imaging (DTI. While each modality provides valuable clinical information in terms of the presence of diffusion and its directionality, both techniques are limited to assuming an ideal Gaussian distribution for water displacement with no intermolecular interactions. This assumption neglects pathological processes that are not Gaussian therefore reducing the amount of potentially clinically relevant information. Additions to the Gaussian distribution measured by the excess kurtosis, or peakedness, of the probabilistic model provide a better understanding of the underlying cellular structure. The objective of this work is to provide mathematical and experimental evidence that Diffusion Kurtosis Imaging (DKI can offer additional information about the micromolecular environment of the pediatric spinal cord. This is accomplished by a more thorough characterization of the nature of random water displacement within the cord. A novel DKI imaging sequence based on a tilted 2D spatially selective radio frequency pulse providing reduced field of view (FOV imaging was developed, implemented, and optimized on a 3 Tesla MRI scanner, and tested on pediatric subjects (healthy subjects: 15; patients with spinal cord injury (SCI:5. Software was developed and validated for post processing of the DKI images and estimation of the tensor parameters. The results show statistically significant differences in mean kurtosis (p < 0.01 and radial kurtosis (p < 0.01 between healthy subjects and subjects with SCI. DKI provides incremental and novel information over conventional diffusion acquisitions when coupled with higher order estimation

  17. Targeted diagnostic magnetic nanoparticles for medical imaging of pancreatic cancer.

    Science.gov (United States)

    Rosenberger, I; Strauss, A; Dobiasch, S; Weis, C; Szanyi, S; Gil-Iceta, L; Alonso, E; González Esparza, M; Gómez-Vallejo, V; Szczupak, B; Plaza-García, S; Mirzaei, S; Israel, L L; Bianchessi, S; Scanziani, E; Lellouche, J-P; Knoll, P; Werner, J; Felix, K; Grenacher, L; Reese, T; Kreuter, J; Jiménez-González, M

    2015-09-28

    Highly aggressive cancer types such as pancreatic cancer possess a mortality rate of up to 80% within the first 6months after diagnosis. To reduce this high mortality rate, more sensitive diagnostic tools allowing an early stage medical imaging of even very small tumours are needed. For this purpose, magnetic, biodegradable nanoparticles prepared using recombinant human serum albumin (rHSA) and incorporated iron oxide (maghemite, γ-Fe2O3) nanoparticles were developed. Galectin-1 has been chosen as target receptor as this protein is upregulated in pancreatic cancer and its precursor lesions but not in healthy pancreatic tissue nor in pancreatitis. Tissue plasminogen activator derived peptides (t-PA-ligands), that have a high affinity to galectin-1 have been chosen as target moieties and were covalently attached onto the nanoparticle surface. Improved targeting and imaging properties were shown in mice using single photon emission computed tomography-computer tomography (SPECT-CT), a handheld gamma camera, and magnetic resonance imaging (MRI).

  18. Infrared imaging diagnostics for intense pulsed electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao; Shen, Jie; Liu, Wenbin; Zhong, Haowen; Zhang, Jie; Zhang, Gaolong; Le, Xiaoyun, E-mail: xyle@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); International Research Center for Nuclei and Particles in the Cosmos, Beihang University, Beijing 100191 (China); Qu, Miao; Yan, Sha [Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

    2015-08-15

    Infrared imaging diagnostic method for two-dimensional calorimetric diagnostics has been developed for intense pulsed electron beam (IPEB). By using a 100-μm-thick tungsten film as the infrared heat sink for IPEB, the emitting uniformity of the electron source can be analyzed to evaluate the efficiency and stability of the diode system. Two-dimensional axisymmetric finite element method heat transfer simulation, combined with Monte Carlo calculation, was performed for error estimation and optimization of the method. The test of the method was finished with IPEB generated by explosive emission electron diode with pulse duration (FWHM) of 80 ns, electron energy up to 450 keV, and a total beam current of over 1 kA. The results showed that it is possible to measure the cross-sectional energy density distribution of IPEB with energy sensitivity of 0.1 J/cm{sup 2} and spatial resolution of 1 mm. The technical details, such as irradiation protection of bremsstrahlung γ photons and the functional extensibility of the method were discussed in this work.

  19. Infrared imaging diagnostics for intense pulsed electron beam.

    Science.gov (United States)

    Yu, Xiao; Shen, Jie; Qu, Miao; Liu, Wenbin; Zhong, Haowen; Zhang, Jie; Yan, Sha; Zhang, Gaolong; Le, Xiaoyun

    2015-08-01

    Infrared imaging diagnostic method for two-dimensional calorimetric diagnostics has been developed for intense pulsed electron beam (IPEB). By using a 100-μm-thick tungsten film as the infrared heat sink for IPEB, the emitting uniformity of the electron source can be analyzed to evaluate the efficiency and stability of the diode system. Two-dimensional axisymmetric finite element method heat transfer simulation, combined with Monte Carlo calculation, was performed for error estimation and optimization of the method. The test of