Quantitative fat and R2* mapping in vivo to measure lipid-rich necrotic core and intraplaque hemorrhage in carotid atherosclerosis

Purpose: The aim of this work was to quantify the extent of lipid-rich necrotic core (LRNC) and intraplaque hemorrhage (IPH) in atherosclerotic plaques. Methods: Patients scheduled for carotid endarterectomy underwent four-point Dixon and T1-weighted magnetic resonance imaging (MRI) at 3 Tesla. Fat and R2* maps were generated from the Dixon sequence at the acquired spatial resolution of 0.60 × 0.60 × 0.70 mm voxel size. MRI and three-dimensional (3D) histology volumes of plaques were registered. The registration matrix was applied to segmentations denoting LRNC and IPH in 3D histology to split plaque volumes in regions with and without LRNC and IPH. Results: Five patients were included. Regarding volumes of LRNC identified by 3D histology, the average fat fraction by MRI was significantly higher inside LRNC than outside: 12.64 ± 0.2737% versus 9.294 ± 0.1762% (mean ± standard error of the mean [SEM]; P < 0.001). The same was true for IPH identified by 3D histology, R2* inside versus outside IPH was: 71.81 ± 1.276 s−1 versus 56.94 ± 0.9095 s−1 (mean ± SEM; P < 0.001). There was a strong correlation between the cumulative fat and the volume of LRNC from 3D histology (R2 = 0.92) as well as between cumulative R2* and IPH (R2 = 0.94). Conclusion: Quantitative mapping of fat and R2* from Dixon MRI reliably quantifies the extent of LRNC and IPH

Environnement logiciel pour l assistance à l autonomie à domicile (gestion de la dynamique et de l incertitude pour la fourniture sémantique en temps réel de services d assistance)

L hétérogénéité des environnements ainsi que la diversité des profils et des besoins des patients représentent des contraintes majeures qui remettent en question l utilisation à grande échelle des systèmes d assistance à l autonomie à domicile (AAL). En effet, afin de répondre à l évolution de l état des patients et de leurs besoins humains, les environnements AAL sont en évolution continue par l introduction ou la disparition de capteurs, de dispositifs d interaction et de services d assistance. Par conséquent, une plateforme générique et dynamique capable de s adapter à différents environnements et d intégrer de nouveaux capteurs, dispositifs d interaction et services d assistance est requise. La mise en œuvre d un tel aspect dynamique peut produire une situation d incertitude dérivée des problèmes techniques liés à la fiabilité des capteurs ou à des problèmes de réseau. Par conséquent, la notion d incertitude doit être introduite dans la représentation de contexte et la prise de décision afin de faire face à ce problème. Au cours de cette thèse, j ai développé une plateforme dynamique et extensible capable de s adapter à différents environnements et aux besoins des patients. Ceci a été réalisé sur la base de l approche Plug&Play sémantique que j ai proposé. Afin de traiter le problème d incertitude de l information lié à des problèmes techniques, j ai proposé une approche de mesure d incertitude en utilisant les caractéristiques intrinsèques des capteurs et leurs comportements fonctionnels. J ai aussi fourni un modèle de représentation sémantique et de raisonnement avec incertitude associé avec la théorie de Dempster-Shafer (DST) pour la prise de décisionThe heterogeneity of the environments as well as the diversity of patients needs and profiles are major constraints that challenge the spread of ambient assistive living (AAL) systems. AAL environments are usually evolving by the introduction or the disappearance of sensors, devices and assistive services to respond to the evolution of patients conditions and human needs. Therefore, a generic framework that is able to adapt to such dynamic environments and to integrate new sensors, devices and assistive services at runtime is required. Implementing such a dynamic aspect may produce an uncertainty derived from technical problems related to sensors reliability or network problems. Therefore, a notion of uncertain should be introduced in context representation and decision making in order to deal with this problem. During this thesis, I have developed a dynamic and extendible framework able to adapt to different environments and patients needs. This was achieved based on my proposed approach of semantic Plug&Play mechanism. In order to handle the problem of uncertain information related to technical problems, I have proposed an approach for uncertainty measurement based on intrinsic characteristics of the sensors and their functional behaviors, then I have provided a model of semantic representation and reasoning under uncertainty coupled with the Dempster-Shafer Theory of evidence (DST) for decision makingEVRY-INT (912282302) / SudocSudocFranceF

Kohdennusohjelman optimointi pään magneetti- ja tietokonetomografiakuville

In this thesis work, the aim was to find a robust, optimal rigid registration process to accurately and automatically align computed tomography (CT) and magnetic resonance (MR) images of the brain. For patients undergoing, for example, stereoelectroencephalography (epilepsy patients) or implantation of stimulating electrodes in the brain (Parkinson’s patients), it is crucial to be able to combine information from low-dose CT and MR with great precision. Registration was performed with SimpleITK interface to the image registration framework of the United States National Library of Medicine Insight Segmentation and Registration Toolkit (ITK). In the optimization process an existing SimpleITK example was used as a basis for the registration algorithm, which was then optimized one block at a time beginning with the initial alignment. Registration accuracy was determined by comparing the automatic transform of our registration algorithm to the transform of a semiautomatic registration performed with a semiautomatic ITK based software, ipcWorkstation, which is used and developed in HUS Medical Imaging Center. As a result, a robust rigid registration algorithm was developed. The maximum registration errors with the final algorithm were less than 2 mm for 7 out of 15 and less than 4 mm for 12 out of 15 patients. The algorithm performs registration up to initial rotations of 45 degrees. The fast development of automated registration algorithm presented in this thesis appears promising to be used for other applications as well. This kind of block-wise optimization pattern could be used to optimize the registration either for images of other parts of the body or for other imaging modalities such as positron emission tomography (PET) and MR.Tämän diplomityön tarkoituksena oli löytää optimaalinen ja automaattinen tietokonetomografia- ja magneettikuvien kohdennusmenetelmä. Kohdennus suoritettiin käyttäen hyväksi SimpleITK-ohjelmakirjastoa, joka perustuu ITK kuvakohdennus ohjelmakirjastoon (engl. the United States National Library of Medicine Insight Segmentation and Registration Toolkit). Optimointi aloitettiin SimpleITKesimerkin pohjalta, jonka parametreja optimoitiin osa kerrallaan lähtien liikkeelle kohdennuksen alustuksesta. Kohdennustarkkuus määritettiin vertaamalla optimoidulla kohdennusohjelmalla saatua automaattista muunnosmatriisia puoliautomaattisella menetelmällä saatuun muunnosmatriisiin. Puoliautomaattinen muunnos tehtiin HUS-Kuvantamisessa kehitetyllä ipcWorkstation-ohjelmalla, joka myös perustuu ITK-ohjelmakirjastoon. Työn tuloksena saatiin luotettavasti toimiva jäykän kuvakohdennuksen suorittava algoritmi, joka pohjautuu SimpleITK:n Python-kirjastoon. Seitsemällä 15 potilaasta suurin kohdennusvirhe oli alle 2 mm ja 12:lla 15 potilaasta alle 4 mm. Kohdennus onnistuu jopa 45 asteen lähtökohtaisilla kulmaeroilla. Työssä käytettyä nopeaa algoritmikehitystekniikkaa voitaisiin käyttää optimointiin muillekin sovelluksille. Tulevaisuudessa algoritmioptimointia osa kerrallaan voisi hyödyntää kohdennusparametrien optimointiin jonkin muun vartalon alueen rakenteellisten kuvien kohdennukseen tai eri kuvamodaliteettien kohdennukseen kuten positroniemissiotomografia- ja magneettikuvien kohdennukseen

NIH-NSF Visualization Research Challenges Report

Engineering and Applied Science

Opportunities And Challenges of E-Health and Telemedicine Via Satelite

The introduction of Information and Communication Technology (ICT) in the health scenario is instrumental for the development of sustainable services of direct benefit for the European citizen. The setting up of satellite based applications will enhance rapidly the decentralisation and the enrichment of the European territory driving it towards a homogenous environment for healthcare

Augmented Reality

Augmented Reality (AR) is a natural development from virtual reality (VR), which was developed several decades earlier. AR complements VR in many ways. Due to the advantages of the user being able to see both the real and virtual objects simultaneously, AR is far more intuitive, but it's not completely detached from human factors and other restrictions. AR doesn't consume as much time and effort in the applications because it's not required to construct the entire virtual scene and the environment. In this book, several new and emerging application areas of AR are presented and divided into three sections. The first section contains applications in outdoor and mobile AR, such as construction, restoration, security and surveillance. The second section deals with AR in medical, biological, and human bodies. The third and final section contains a number of new and useful applications in daily living and learning

Activity profiling for minimally invasive surgery

Imperial Users onl