Search results for "Diffusion"
showing 10 items of 1615 documents
Liver intravoxel incoherent motion (IVIM) magnetic resonance imaging: a comprehensive review of published data on normal values and applications for …
2017
A comprehensive literature review was performed on liver intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) technique and its applications. Heterogeneous data have been reported. IVIM parameters are magnetic field strength dependent to a mild extent. A lower Dslow (D) value at 3 T than at 1.5 T and higher perfusion fraction (PF) value at 3 T than at 1.5 T were noted. An increased number of b values are associated with increased IVIM parameter measurement accuracy. With the current status of art, IVIM technique is not yet capable of detecting early stage liver fibrosis and diagnosing liver fibrosis grades, nor can it differentiate liver tumors. Though IVIM parameters show p…
What have we learnt 50 years after the first Fontan procedure?
2020
The Fontan procedure is often the only definitive palliative surgical option for patients with a variety of complex CHD sharing in common, a single, dominant ventricle. In recent decades, imaging and therapeutic improvement have played a crucial role in those patients in whom many complications can hamper their life. After 50 years from the first procedure, heart transplantation remains the only definitive treatment for those with a failing Fontan circulation.
Magnetic Resonance Imaging Derived Biomarkers of IDH Mutation Status and Overall Survival in Grade III Astrocytomas
2020
The evaluation of the isocitrate dehydrogenase (IDH) mutation status in the glioma decision-making process has diagnostic, prognostic and therapeutic implications. The aim of this study was to evaluate whether conventional magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) can noninvasively predict the most common IDH mutational status (R132H) in GIII-astrocytomas and the overall survival (OS). Hence, twenty-two patients (9-F, 13-M) with a histological diagnosis of GIII-astrocytoma and evaluation of IDH-mutation status (12-wild type, 10-mutant) were retrospectively evaluated. Imaging studies were reviewed for the morphological feature and mean ADC values (ADCm). Stati…
La classificació de la documentació parlamentària de les Corts Valencianes: la funció de control al Consell.
2008
El dinamisme necessari en una institució parlamentària com les Corts Valencianes requereix de l'organització del fons documental i, per tant, la necessitat d'elaborar un sistema de gestió documental integral. L'objectiu és facilitar la recuperació d'informació parlamentària per a la millora de la gestió, la presa de decisions, l'enriquiment dels debats i la investigació sobre la institució. L'accés a la documentació facilita també el coneixement de les funcions de la cambra, i l'aproximació dels ciutadans a les Corts. Això s'ha concretat en l'elaboració d'un quadre de classificació per a descriure el fons documental i gestionar-ne la recuperació, l'eliminació o la conservació. La metodologi…
Tracer migration in crystalline rock : application to geological barriers of nuclear waste storage
2016
This work deals with transport of radionuclides in the geosphere. The subject is investigated through characterisation of water conducting fractures, determining of rock transport properties and development of new methods for characterising geological samples. Here, as is often the case, radionuclide transport is investigated indirectly by characterising the structures, where the transport takes place, and directly by measuring transport properties in the gas phase. First water conducting fractures of three different types and the rock matrix surrounding them were analysed through rock samples from Olkiluoto. The analysis was done using X-ray tomography, the 14C-PMMA autoradiography techniq…
Numerical methods for pricing options under jump-diffusion processes
2013
Journal of Economics and Management Research, Vol. 4/5
2016
Deinstitutionalization revisited
2021
PurposeThe purpose of this paper is to offer a new analysis and understanding of the notion of deinstitutionalization. Deinstitutionalization of taken-for-granted practices as a natural consequence of ever-increasing entropy seems to directly contradict the major institutional thesis, namely, that over time isomorphic forces increase and, as a result, possibilities for deinstitutionalization decrease culminating in the impossibility of abandoning in highly institutionalized fields.Design/methodology/approachThis paper is conceptual in nature. Oliver’s 1992 paper on deinstitutionalization is taken as a key text on the subject and as a starting point for building an alternative theory of dein…
A CNN Adaptive Model to Estimate PM10 Monitoring
2006
In this work we introduce a model for studying the distribution and control of atmospheric pollution from PM10. The model is based on the use of a cellular neural network (CNN) and more precisely on the integration of the mass-balance equation; at the same time it simulates the scenario regarding a planar grid describing the whole studied area (the city of Palermo) by means of a CNN and a set of Bayesian networks. The CNN allows us to define a grid system whose dynamic evolution is a redefinition of the diffusion equation that considers contributions coming from near cells for each element of the grid. Dynamics of each cell is influenced by meteorological effects and by parameters related t…
Valeur de l’IRM de diffusion pour caractériser les petites masses rénales (< 3cm)
2012
Objectifs: Décrire l’aspect des masses rénales (< 3cm) en imagerie de diffusion et déterminer le rôle de l’ADC pour la différentiation entre lésion maligne et bénigne. Matériels et méthodes: 47 tumeurs rénales < 3cm (23 malignes, 24 bénignes) furent explorées en IRM 3T incluant en sus du protocole habituel une séquence de diffusion (b1000). Une analyse rétrospective qualitative et quantitative (ADC) fut réalisée avec corrélation anatomopathologique et tests statistiques pour déterminer l’efficacité de la valeur d’ADC pour caractériser la lésion. Résultats: En diffusion, toutes les masses étaient hyperintenses au parenchyme sain. L’ADC moyen des CC RCC était supérieur à celui des angiomyolip…