Search results for "MRI"

Graph cut-based method for segmenting the left ventricle from MRI or echocardiographic images

2017

International audience; In this paper, we present a fast and interactive graph cut method for 3D segmentation of the endocardial wall of the left ventricle (LV) adapted to work on two of the most widely used modalities: magnetic resonance imaging (MRI) and echocardiography. Our method accounts for the fundamentally different nature of both modalities: 3D echocardiographic images have a low contrast, a poor signal-to-noise ratio and frequent signal drop, while MR images are more detailed but also cluttered and contain highly anisotropic voxels. The main characteristic of our method is to work in a 3D Bezier coordinate system instead of the original Euclidean space. This comes with several ad…

Segmentation Integrating Watershed and Shape Priors Applied to Cardiac Delayed Enhancement MR Images

2017

International audience; Background: In recent years, there has been a rapid rise in the use of shape priors applied to segmentation process of medical images. Previous approaches on left ventricle segmentation from Delayed-Enhancement Magnetic Resonance Imaging (DE-MRI) have focused on the extraction of myocardium or just diseased region in short axis orientation. However these studies did not take into account the segmentation of non-diseased myocardium from DE-MRI. The segmentation of non-diseased myocardium from DE-MRI, has some useful applications. For instance it can simplify the PET-MR registration process.Methods: This paper presents a novel semi-automatic segmentation method of non-…

Advanced techniques in Magnetic Resonance Imaging: characterization of non-gaussian water diffusion using DIFFUSION KURTOSIS IMAGING (DKI)

2014

Looking into the architecture of the brain with MRI: quantification of non-Gaussian water diffusion by Diffusion Kurtosis Imaging (DKI)

2015

The aim of this work is the definition of an MRI protocol for Diffusion Kurtosis Imaging (DKI) by using a 1.5T clinical scanner and the development of a software for DKI analysis.

Diffusion Kurtosis Imaging: prime applicazioni cliniche in ambito neuroradiologico

2014

Alaraajojen luun mineraalipitoisuuden ja polven nivelruston väliset yhteydet postmenopausaalisilla naisilla

2011

Tämän poikkileikkaustutkimuksen tarkoituksena oli selvittää luuston (reisiluun kaula, lanneranka L2-L4) mineraalitiheysarvojen ja polven nivelruston (reisiluu, sääriluu) eheyttä kuvaavien dGEMRIC-arvojen välistä yhteyttä postmenopausaalisilla naisilla. Tutkimukseen rekrytoitiin 82 naista (keskimääräiseltä iältään 57,7 vuotta, SD 4,2) lehti-ilmoituksen perusteella. Sisäänottokriteerinä oli rtg:llä arvioidun Kellgren-Lawrence-luokituksen (K/L) mukaan ensimmäisen (K/L1) tai toisen (K/L2) asteen lievä polven nivelrikko. Reisiluun kaulan ja lannerangan (L2–L4) BMC-arvot mitattiin DXA-laitteistolla. Tutkimushenkilöillä ei ollut osteoporoosia, jonka kynnysarvona käytettiin T-arvoa >2,5. Tibian ja …

Neuroimaging and electrophysiology meet invasive neurostimulation for causal interrogations and modulations of brain states.

2020

Deep brain stimulation (DBS) has developed over the last twenty years into a highly effective evidenced-based treatment option for neuropsychiatric disorders. Moreover, it has become a fascinating tool to provide illustrative insights into the functioning of brain networks. New anatomical and pathophysiological models of DBS action have accelerated our understanding of neurological and psychiatric disorders and brain functioning. The description of the brain networks arose through the unique ability to illustrate long-range interactions between interconnected brain regions as derived from state-of-the-art neuroimaging (structural, diffusion, and functional MRI) and the opportunity to record…

Physics, Techniques and Review of Neuroradiological Applications of Diffusion Kurtosis Imaging (DKI)

2016

In recent years many papers about diagnostic applications of diffusion tensor imaging (DTI) have been published. This is because DTI allows to evaluate in vivo and in a non-invasive way the process of diffusion of water molecules in biological tissues. However, the simplified description of the diffusion process assumed in DTI does not permit to completely map the complex underlying cellular components and structures, which hinder and restrict the diffusion of water molecules. These limitations can be partially overcome by means of diffusion kurtosis imaging (DKI). The aim of this paper is the description of the theory of DKI, a new topic of growing interest in radiology. DKI is a higher or…

Diffusion-weighted MRI of colo-rectal liver metastases treated by new anti-angiogenetic chemotherapy

2009

Potential implementation of reservoir computing models based on magnetic skyrmions

2018

Reservoir Computing is a type of recursive neural network commonly used for recognizing and predicting spatio-temporal events relying on a complex hierarchy of nested feedback loops to generate a memory functionality. The Reservoir Computing paradigm does not require any knowledge of the reservoir topology or node weights for training purposes and can therefore utilize naturally existing networks formed by a wide variety of physical processes. Most efforts prior to this have focused on utilizing memristor techniques to implement recursive neural networks. This paper examines the potential of skyrmion fabrics formed in magnets with broken inversion symmetry that may provide an attractive phy…