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Results 1 - 50 of 2011
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Bae Sung-Ho - - 2014
In this paper, we propose a new DCT-based just noticeable difference (JND) profile incorporating the spatial contrast sensitivity function, the luminance adaptation effect, and the contrast masking (CM) effect. The proposed JND profile overcomes two limitations of conventional JND profiles: 1) the CM JND models in the conventional JND profiles ...
Ahlgren André A Department of Medical Radiation Physics, Lund University, Lund, - - 2014
Quantitative perfusion MRI based on arterial spin labeling (ASL) is hampered by partial volume effects (PVEs), arising due to voxel signal cross-contamination between different compartments. To address this issue, several partial volume correction (PVC) methods have been presented. Most previous methods rely on segmentation of a high-resolution T1 -weighted morphological ...
Singha Suman S Maritime Security Lab, Remote Sensing Technology Institute, German Aerospace Center (DLR), Germany. Electronic address: - - 2014
Continuous operational monitoring by means of remote sensing contributes significantly towards less occurrence of oil spills over European waters however, operational activities show regular occurrence of accidental and deliberate oil spills over the North Sea, particularly from offshore platform installations. Since the areas covered by oil spills are usually large ...
Luterbacher Jeremy S JS Department of Chemical and Biomolecular Engineering, Olin Hall, Cornell University, Ithaca, NY, - - 2014
Enzymatic hydrolysis is one of the critical steps in depolymerizing lignocellulosic biomass into fermentable sugars for further upgrading into fuels and/or chemicals. However, many studies still rely on empirical trends to optimize enzymatic reactions. An improved understanding of enzymatic hydrolysis could allow research efforts to follow a rational design guided ...
Haq Nandinee Fariah NF University of British Columbia, Vancouver, BC, - - 2014
Magnetic resonance imaging (MRI), particularly dynamic contrast enhanced (DCE) imaging, has shown great potential in prostate cancer diagnosis and staging. In the current practice of DCE-MRI, diagnosis is based on quantitative parameters extracted from the series of T1-weighted images acquired after the injection of a contrast agent. To calculate these ...
Leten Cindy C Department of Imaging and Pathology, Biomedical MRI, KU Leuven, O&N1, Herestraat 49, P.O. Box 505, 3000, Louvain, - - 2014
Blood brain barrier (BBB) disruption is used (pre)clinically as a measure for brain tumor malignancy and grading. During treatment it is one of the parameters followed rigorously to assess therapeutic efficacy. In animal models, both invasive and non-invasive methods are used to determine BBB disruption, among them Evans blue injection ...
Debbaut Charlotte C Biofluid, Tissue and Solid Mechanics for Medical Applications (bioMMeda), Department of Electronics and Information Systems, iMinds Medical IT Department, Ghent University, Ghent - - - 2014
Hypothermic machine perfusion (HMP) is reviving as a better preservation method for donor livers than the golden standard of cold storage, but still faces challenges such as the risk for endothelial damage and flow competition between the arterial and portal venous inflow. Therefore, we previously developed an electrical analog model ...
Sumpf Tilman - - 2014
A model-based reconstruction technique for accelerated T2 mapping with improved accuracy is proposed using undersampled Cartesian spin-echo MRI data. The technique employs an advanced signal model for T2 relaxation that accounts for contributions from indirect echoes in a train of multiple spin echoes. An iterative solution of the nonlinear inverse ...
Yan Xu X Key Laboratory of Brain Functional Genomics (MOE & STCSM), Key Laboratory of Magnetic Resonance, Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai 20062, China. Electronic address: - - 2014
Diffusion kurtosis imaging (DKI) is a new model in magnetic resonance imaging (MRI) characterizing restricted diffusion of water molecules in living tissues. We propose a method for fast estimation of the DKI parameters. These parameters - apparent diffusion coefficient (ADC) and apparent kurtosis coefficient (AKC) - are evaluated using an ...
Kumar Mohit - - 2014
This text provides several applications scenarios of introduced signals' modeling and analysis framework to solve the practical problems. Some of the challenging practical problems related to signal/data processing have been formulated in a manner that the negative free energy maximizing filtering and variational information maximizing analysis algorithms of Kumar et ...
Chen Weijie W Division of Imaging and Applied Mathematics Office of Science and Engineering Laboratories Center for Devices and Radiological Health Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, Maryland, 20993 United - - 2014
Objectives: In multi-reader, multi-case (MRMC) receiver operating characteristic (ROC) studies for evaluating medical imaging systems, the area under the curve (AUC) is often used as a summary metric. Due to the limitations of AUC, plotting the average ROC curve to accompany the rigorous statistical inference on AUC is recommended. The ...
Markus Michelle A MA Bruker BioSpin Corporation, Billerica, MA, - - 2014
A method was developed to distinguish Vaccinium species based on leaf extracts using nuclear magnetic resonance spectroscopy. Reference spectra were measured on leaf extracts from several species, including lowbush blueberry (Vaccinium angustifolium), oval leaf huckleberry (Vaccinium ovalifolium), and cranberry (Vaccinium macrocarpon). Using principal component analysis, these leaf extracts were resolved ...
Orsingher Laura L From the *Department of Medical Physics, Parma University Hospital Trust; Parma, Italy; †Università Cattolica del S. Cuore, Roma; and ‡Department of Neuroradiology, Parma University Hospital Trust; Parma, - - 2014
There are several potential sources of difference that can influence the reproducibility of magnetic resonance (MR) perfusion values. We aimed to investigate the reproducibility and variability of dynamic susceptibility contrast (DSC) MR imaging (MRI) parameters obtained from identical source data by using 2 commercially available software applications with different postprocessing ...
Dikaios Nikolaos N Centre for Medical Imaging, University College London, 250 Euston Road, NW1 2PG London, UK; Centre for Medical Image Computing, University College London, Gower Street, WC1E 6BT London, UK. Electronic address: - - 2014
The Magnetic Resonance Imaging (MRI) signal can be made sensitive to functional parameters that provide information about tissues. In dynamic contrast enhanced (DCE) MRI these functional parameters are related to the microvasculature environment and the concentration changes that occur rapidly after the injection of a contrast agent. Typically DCE images ...
Zarinabad Niloufar N Division of Imaging Sciences and Biomedical Engineering, King's College London BHF Centre of Excellence, NIHR Biomedical Research Centre and Wellcome Trust and EPSRC Medical Engineering Centre at Guy's and St. Thomas' NHS Foundation Trust, The Rayne Institute, St. Thomas' Hospital, London, SE1 7EH, - - 2014
High-resolution myocardial perfusion analysis allows for preserving spatial information with excellent sensitivity for subendocardial ischemia detection. However, it suffers from low signal-to-noise ratio. Commonly, spatial averaging is used to increase signal-to-noise ratio. This bears the risk of losing information about the extent, localization and transmurality of ischemia. This study investigates ...
Nelson Kevin K Kevin Nelson, Christopher Bobba, Samir Ghadiali, Department Biomedical Engineering, The Ohio State University, Columbus, OH 43210, United - - 2014
Ex vivo lung perfusion (EVLP) is a powerful experimental model for isolated lung research. EVLP allows for the lungs to be manipulated and characterized in an external environment so that the effect of specific ventilation/perfusion variables can be studied independent of other confounding physiologic contributions. At the same time, EVLP ...
Jones Andrew Edward - - 2014
In this paper we demonstrate the use of pattern recognition and machine learning techniques to determine the reactor design from which spent reactor fuel has originated. This has been done using the isotopic and elemental composition of the sample and proves to be very useful in the field of nuclear ...
Randtke Edward A EA Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, - - 2014
Magnetic resonance imaging (MRI) contrast media that are detected via chemical exchange saturation transfer (CEST) often require an accurate estimation of their chemical exchange rate, kex . A variety of analysis methods have been proposed to estimate kex , including the nonlinear QUEST analysis method that evaluates the CEST amplitude ...
Tosic Ivana - - 2014
This paper presents a method for learning overcomplete dictionaries of atoms composed of two modalities that describe a 3D scene: 1) image intensity and 2) scene depth. We propose a novel joint basis pursuit (JBP) algorithm that finds related sparse features in two modalities using conic programming and we integrate ...
He Wei W Tsinghua University, School of Medicine, Department of Biomedical Engineering, Beijing 100084, - - 2014
ABSTRACT. In conventional fluorescence molecular tomography, the distribution of fluorescent contrast agents is reconstructed with the assumption of constant concentration during data acquisition for each image frame. However, the concentration of fluorescent contrast target is usually time-varying in experiments or in-vivo studies. In this case, the reconstruction methods cannot be ...
Qi Lin - - 2014
The majority of work on the perception of gloss has been performed using smooth surfaces (e.g., spheres). Previous studies that have employed more complex surfaces reported that increasing mesoscale roughness increases perceived gloss [Psychol. Sci.19, 196 (2008), J. Vis.10(9), 13 (2010), Curr. Biol.22, 1909 (2012)]. We show that the use ...
Yap Pew-Thian - - 2014
Statistics derived from diffusion magnetic resonance imaging (MRI) data are often highly non-linear and non-Gaussian with unknown complex distributions. In estimating the sampling distributions of these statistics, many existing techniques are limited by their reliance on models that assume normality and that are yet to be verified in complex situations ...
Otazo Ricardo R Department of Radiology, New York University School of Medicine, New York, NY, - - 2014
To apply the low-rank plus sparse (L+S) matrix decomposition model to reconstruct undersampled dynamic MRI as a superposition of background and dynamic components in various problems of clinical interest. The L+S model is natural to represent dynamic MRI data. Incoherence between k-t space (acquisition) and the singular vectors of L ...
Zhu Di - - 2014
Simple circuit models provide valuable insight into the properties of plasmonic resonators. Yet, it is unclear how the circuit elements can be extracted and connected in the model in an intuitive and accurate manner. Here, we present a detailed treatment for constructing such circuits based on energy and charge oscillation ...
Feng Dai - - 2014
Various works have used magnetic resonance imaging (MRI) tissue classification extensively to study a number of neurological and psychiatric disorders. Various noise characteristics and other artifacts make this classification a challenging task. Instead of splitting the procedure into different steps, we extend a previous work to develop a unified Bayesian ...
Sarraf Michel M Université Joseph Fourier, Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale INSERM-U836, Bâtiment Edmond J. Safra, Chemin Fortuné Ferrini, Grenoble, France; CLINATEC, Commissariat à l'énergie atomique et aux énergies alternatives, MINATEC Campus, Grenoble, France; Université Saint Joseph-Faculté des sciences, Département de physique, campus des sciences et technologies, Mar Roukos, Mkallès, - - 2014
This study demonstrates how to quantify the tumor blood volume fraction (BVf) using the dynamic Rapid-Steady-State-T1 (RSST1 )-MRI method despite contrast agent (CA) leakage and without arterial input function (AIF) determination. For vasculature impermeable to CAs, the BVf is directly quantified from the RSST1 signal amplitude. In case of CA ...
Macháň Radek R Departments of Biological Sciences and Chemistry and Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, - - 2014
Fluorescence correlation spectroscopy (FCS) is a widely used technique in biophysics and has helped address many questions in the life sciences. It provides important advantages compared to other fluorescence and biophysical methods. Its single molecule sensitivity allows measuring proteins within biological samples at physiological concentrations without the need of overexpression. ...
Alsop David C DC Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, - - 2014
This review provides a summary statement of recommended implementations of arterial spin labeling (ASL) for clinical applications. It is a consensus of the ISMRM Perfusion Study Group and the European ASL in Dementia consortium, both of whom met to reach this consensus in October 2012 in Amsterdam. Although ASL continues ...
Oleszkiewicz Simon - - 2014
This study is on how to elicit intelligence from human sources. We compared the efficacy of two human intelligence gathering techniques: the Scharff-technique (conceptualized as four different tactics) and the Direct Approach (a combination of open and direct questions). Participants (N = 60) were asked to take on the role ...
Sasaki Naoki N Department of Applied Chemistry, Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan; Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan. Electronic address: - - 2014
We report a microvascular-interstitium model on microfluidic devices to study leakage of drugs from blood vessels under in vivo-like flow conditions. We employed magnetic resonance imaging to demonstrate the compatibility of the model for experimental animals and humans. We observed transport of two types of different molecular-weight contrast agents into ...
Kamor A A School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA and Centre de Physique Théorique, CNRS, Aix-Marseille Université, Campus de Luminy, Case 907, 13009 Marseille, - - 2014
We present a purely classical recollision scenario, i.e., without tunneling, which, in contrast to the standard three-step model, takes into account the ionic core potential fully at all stages of the recollision process and is valid at all intensities. We find that a key periodic orbit drives the recollisions by ...
Bafarawa Buhari B Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United - - 2014
The typical approach to analysing raw data, from common pore characterization methods such as gas sorption and mercury porosimetry, to obtain pore size distributions for disordered porous solids generally makes several critical assumptions that impact the accuracy of the void space descriptors thereby obtained. These assumptions can lead to errors ...
Yang Xue - - 2014
Modern statistical inference techniques may be able to improve the sensitivity and specificity of resting state functional magnetic resonance imaging (rs-fMRI) connectivity analysis through more realistic assumptions. In simulation, the advantages of such methods are readily demonstrable. However, quantitative empirical validation remains elusive in vivo as the true connectivity patterns ...
Schwab Felix F Josef Lissner Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany; Munich Heart Alliance, Munich, - - 2014
To investigate and compare several quantification methods of myocardial perfusion measurements, paying special attention to the relation between the techniques and the required measurement duration. Seven patients underwent contrast-enhanced rest and stress cardiac perfusion measurements at 3T. Three slices were acquired in each patient and were divided into 16 segments, ...
Mertzanidou Thomy T Centre for Medical Image Computing, University College London, Gower Street, WC1E 6BT London, UK. Electronic address: - - 2014
Determining corresponding regions between an MRI and an X-ray mammogram is a clinically useful task that is challenging for radiologists due to the large deformation that the breast undergoes between the two image acquisitions. In this work we propose an intensity-based image registration framework, where the biomechanical transformation model parameters ...
Gilani Hammad H International Centre for Integrated Mountain Development, GPO Box 3226, Kathmandu, Nepal; School of Geomatics, Liaoning Technical University, 47 Zhonghua Road, Fuxin, Liaoning Province, China. Electronic address: - - 2014
Land cover (LC) is one of the most important and easily detectable indicators of change in ecosystem services and livelihood support systems. This paper describes the decadal dynamics in LC changes at national and sub-national level in Bhutan derived by applying object-based image analysis (OBIA) techniques to 1990, 2000, and ...
Becker S M A SM Weierstrass Institute for Applied Analysis and Stochastics, Berlin, - - 2014
We present a novel multi-shell position orientation adaptive smoothing (msPOAS) method for diffusion-weighted magnetic resonance data. Smoothing in voxel and diffusion gradient space is embedded in an iterative adaptive multiscale approach. The adaptive character avoids blurring of the inherent structures and preserves discontinuities. The simultaneous treatment of all q-shells improves ...
Li Hewei H School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, PR - - 2014
Everted gut sac (EGS) and in situ single-pass intestinal perfusion (SPIP) have been widely used in the study of drug absorption and biopharmaceutical classification systems (BCS). Furthermore, they could also be applied in the research of drug intestinal first-pass metabolism. Since most of Chinese herbal medicines (CHMs) are orally administrated, ...
Kramann Rafael R Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, - - 2014
AKI predicts the future development of CKD, and one proposed mechanism for this epidemiologic link is loss of peritubular capillaries triggering chronic hypoxia. A precise definition of changes in peritubular perfusion would help test this hypothesis by more accurately correlating these changes with future loss of kidney function. Here, we ...
Boruah Dibyajyoti D Department of Pathology, Armed Forces Medical College, Pune-411040, Maharashtra, INDIA. Electronic address: - - 2014
Modifications of nuclear morphology in conjunction with alteration in microvascular configuration are essential features encountered during the progression of glial tumours. In order to gain more insight into tumour biology of gliomas, objectives of the study were selected (a) to correlate morphometrically evaluated nuclear parameters [nuclear area (NA), nuclear perimeter ...
Sjögren Erik E Department of Pharmacy, Uppsala University, Uppsala - - 2014
This review summarizes the current knowledge on anatomy and physiology of the human gastrointestinal tract in comparison with that of common laboratory animals (dog, pig, rat and mouse) with emphasis on in vivo methods for testing and prediction of oral dosage form performance. A wide range of factors and methods ...
Feng Meiyan M School of Biomedical Engineering, Southern Medical University, Guangzhou, - - 2014
To evaluate the performance of region-of-interest (ROI)-based MRI R2* measurements by using the first-moment noise-corrected model (M(1)NCM) to correct the non-central Chi noise in magnitude images from phased arrays for hepatic iron content (HIC) assessment. R2* values were quantified using the M(1)NCM model. Three approaches were employed to determine the ...
Bindschadler Michael M Department of Bioengineering University of Washington, Seattle, WA 98195, US. Department of Radiology, University of Washington, Seattle, WA 98195, - - 2014
Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for ...
Tsai Tsung-Hung - - 2014
Camera-enabled mobile devices are commonly used as interaction platforms for linking the user's virtual and physical worlds in numerous research and commercial applications, such as serving an augmented reality interface for mobile information retrieval. The various application scenarios give rise to a key technique of daily life visual object recognition. ...
Schwen Lars Ole LO Fraunhofer MEVIS, Bremen, - - 2014
The liver is the central organ for detoxification of xenobiotics in the body. In pharmacokinetic modeling, hepatic metabolization capacity is typically quantified as hepatic clearance computed as degradation in well-stirred compartments. This is an accurate mechanistic description once a quasi-equilibrium between blood and surrounding tissue is established. However, this model ...
Yi Boram B Department of Radiology, Ajou University School of Medicine, San 5, Woncheon-dong, Yongtong-gu, Suwon, Gyeonggi-do, 442-749, South - - 2014
To find out any correlation between dynamic contrast-enhanced (DCE) model-based parameters and model-free parameters, and evaluate correlations between perfusion parameters with histologic prognostic factors. Model-based parameters (Ktrans, Kep and Ve) of 102 invasive ductal carcinomas were obtained using DCE-MRI and post-processing software. Correlations between model-based and model-free parameters and between ...
Zöllner Frank G FG Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. Electronic address: - - 2014
To investigate the results of different pharmacokinetic models of a quantitative analysis of renal blood flow (RBF) in acute kidney injury using deconvolution analysis and a two-compartment renal filtration model. MRI data of ten male Lewis rats were analyzed retrospectively. Six animals were subjected to unilateral acute kidney injury and ...
Ramezani Mahdi M Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, BC, Canada, - - 2014
Classification of individuals based on patterns of brain activity observed in functional MRI contrasts may be helpful for diagnosis of neurological disorders. Prior work for classification based on these patterns have primarily focused on using a single contrast, which does not take advantage of complementary information that may be available ...
Richardson Owen C OC Division of Medical Physics, University of Leeds, Leeds, United - - 2014
There is currently no adequate method of mapping physiologic and pathophysiologic tissue albumin concentrations in human subjects. The objective of this study was to devise and evaluate a biomarker of regional albumin concentration using gadofosveset-enhanced MRI. A binding and relaxation model was devised and evaluated in vitro in solutions of ...
Bartoš Michal M Dept. of Biomedical Engineering, Brno Univ. of Technology, Brno, Czech Republic; Inst. of Information Theory and Automation of the Academy of Sciences of the Czech Republic, Prague, Czech Republic. Electronic address: - - 2014
The present trend in dynamic contrast-enhanced MRI is to increase the number of estimated perfusion parameters using complex pharmacokinetic models. However, less attention is given to the precision analysis of the parameter estimates. In this paper, the distributed capillary adiabatic tissue homogeneity pharmacokinetic model is extended by the bolus arrival ...
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