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Image Plane (image + plane)
Selected AbstractsRole of Echocardiography in Percutaneous Occlusion of the Left Atrial AppendageECHOCARDIOGRAPHY, Issue 4 2007Mráz M.D. Percutaneous occlusion of the left atrial appendage (LAA) is a modern alternative for the treatment of patients with atrial fibrillation (AF) and with a high risk of stroke who are not eligible for long-term anticoagulation therapy. Echocardiography plays a significant role in selecting patients, guiding the procedure, and in the postprocedural follow-up. Objectives and methods: To test the role of transesophagoeal echocardiography (TEE) and intracardiac echocardiography (ICE) in facilitating and shortening the procedure. Results: ICE represents a more convenient approach in patients who are not under generally anesthesia and helps to facilitate transseptal puncture. On the other hand, TEE, having the ability to rotate the image plane, helps to better determine the position of the occluder. Conclusions: Echocardiographic guidance of this procedure is essential. Which approach will be preferred will depend on the development of these two methods. [source] An image warping approach to spatio-temporal modellingENVIRONMETRICS, Issue 8 2005Sofia Aberg Abstract In this article we present a spatio-temporal dynamic model that can be realized using image warping. Image warping is a non-linear deformation which maps every point in one image plane to a point in another image plane. Using thin-plate splines, these deformations are defined by how a small set of points is mapped, making the method computationally tractable. In our case the dynamics of the process is modelled by thin-plate spline deformations and how they vary in time. Thus we make no assumption of stationarity in time. Finding the deformation between two images in the space,time series is a trade-off between a good match of the images and a smooth, physically plausible, deformation. This is formulated as a penalized likelihood problem, where the likelihood measures how good the match is and the penalty comes from a prior model on the deformation. The dynamic model we suggest can be used to make forecasts and also to estimate the uncertainties associated with these. An introduction to image warping and thin-plate splines is given as well as an application where the methodology is applied to the problem of nowcasting radar precipitation. Copyright © 2005 John Wiley & Sons, Ltd. [source] Visual servoing of an autonomous helicopter in urban areas using feature trackingJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 3-4 2006Luis Mejías We present the design and implementation of a vision-based feature tracking system for an autonomous helicopter. Visual sensing is used for estimating the position and velocity of features in the image plane (urban features like windows) in order to generate velocity references for the flight control. These visual-based references are then combined with GPS-positioning references to navigate towards these features and then track them. We present results from experimental flight trials, performed in two UAV systems and under different conditions, that show the feasibility and robustness of our approach. © 2006 Wiley Periodicals, Inc. [source] Isotropic Component Trace AnalysisJOURNAL OF NEUROIMAGING, Issue 3 2005Hitoshi Matsuzawa MD ABSTRACT A new method for analyzing diffusion tensor imaging (DTI) of the brain, based on a recently introduced algorithm, lambda chart analysis (LCA), is presented. Pretreatment of a given DTI data set with LCA, which effectively segregates isotropic and aniso tropic components, allows for total removal of the anisotropic component from the DTI data set. The remaining pure isotropic component can therefore be subjected to further analysis simi lar to that applied in the trace histogram method. Deconvolution of the trace function yielded 3 Gaussian elements. Remapping of these 3 deconvoluted isotropic elements back onto the 2-dimensional image plane provided anatomical correlates of each element. The algorithm, referred to here as isotropic com ponent trace analysis, can be used as a pictorial analytic tool, as well as a numerical analytical tool, for the noninvasive assess ment of isotropic parenchymal components. The presented method provides quantitative indices of certain parenchymal parameters with better clarity than currently available methods. A ready-to-use program, EZ-LCA, for this powerful method is provided (available at http://coe.bri.niigata-u.ac.jp). [source] Examination of an unusual grain boundary in CaF2PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2004M.E. Msall Abstract We have examined a grain boundary in CaF2 using Phonon Imaging and Electron Backscatter Diffractometry (EBSD). Unlike the <111> twin boundary typically found in CaF2, the crystal grains on either side of the boundary are not simply related to any principle symmetry directions, and are not related to one another by symmetry operations of the cubic group. In spite of the high degree of misalignment of the crystalline lattices, phonons can pass this grain boundary without excessive energy loss. Phonon images of samples taken from different sections of the grain boundary show that the structural properties of the grain boundary are constant over a large area. Computer simulations of phonon scattering at the interface based on acoustic mismatch models demonstrate that the caustic positions are sensitive to small changes in the relative orientation of the two pieces and to the projection of the grain boundary on the image plane. EBSD gives the needed high precision measurement of the relative orientation, resulting in a superior model of phonon transmission through this very asymmetric interface. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Bisphosphonate-Associated Osteonecrosis of the Jaw: Report of a Task Force of the American Society for Bone and Mineral Research,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2007Sundeep Khosla (Chair) Abstract ONJ has been increasingly suspected to be a potential complication of bisphosphonate therapy in recent years. Thus, the ASBMR leadership appointed a multidisciplinary task force to address key questions related to case definition, epidemiology, risk factors, diagnostic imaging, clinical management, and future areas for research related to the disorder. This report summarizes the findings and recommendations of the task force. Introduction: The increasing recognition that use of bisphosphonates may be associated with osteonecrosis of the jaw (ONJ) led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address a number of key questions related to this disorder. Materials and Methods: A multidisciplinary expert group reviewed all pertinent published data on bisphosphonate-associated ONJ. Food and Drug Administration drug adverse event reports were also reviewed. Results and Conclusions: A case definition was developed so that subsequent studies could report on the same condition. The task force defined ONJ as the presence of exposed bone in the maxillofacial region that did not heal within 8 wk after identification by a health care provider. Based on review of both published and unpublished data, the risk of ONJ associated with oral bisphosphonate therapy for osteoporosis seems to be low, estimated between 1 in 10,000 and <1 in 100,000 patient-treatment years. However, the task force recognized that information on incidence of ONJ is rapidly evolving and that the true incidence may be higher. The risk of ONJ in patients with cancer treated with high doses of intravenous bisphosphonates is clearly higher, in the range of 1,10 per 100 patients (depending on duration of therapy). In the future, improved diagnostic imaging modalities, such as optical coherence tomography or MRI combined with contrast agents and the manipulation of image planes, may identify patients at preclinical or early stages of the disease. Management is largely supportive. A research agenda aimed at filling the considerable gaps in knowledge regarding this disorder was also outlined. [source] | ||||||||||