Search results for "MRI."
showing 10 items of 591 documents
Functionnalized magnetite nanoparticles for bimodal imaging MRI/PET
2015
Functionalized magnetite nanoparticles for bimodal MRI/PET imagingSuperParamagnetic Iron Oxide Nanoparticles (SPIONs) have been widely studied in the biomedical field due to their promising application as nanodrugs and MRI (Magnetic Resonance Imaging) contrast agents (T2). In this study, magnetite (Fe3O4) nanoparticles have been developed for use as contrast agents for MRI/PET (Positron emission tomography) double imaging. First, functionalized stable superparamagnetic SPIONs have been synthesized in a continuous hydrothermal reactor. During the synthesis, hydrophilic agents (citric acid, LDOPA, DHCA and PHA) have been grafted on the surface of the nanoparticles. The functionalization of th…
Tumor enhancement at contrast-enhanced CT and Gd-enhanced MRI for the assessment of treatment response of hepatocellular carcinoma (HCC) after sorafe…
2012
Scopo: To investigate whether arterial enhancement of advanced HCC during pre-treatment and follow-up contrast-enhanced CT (CECT) or Gd-enhanced MRI (Gd-MRI) can be used to predict tumor response to sorafenib. Materiali e metodi: Seventeen patients (12M, 5F; mean age: 69 years) receiving sorafenib for inoperable HCC between 2007 and 2010 were included. Median interval time between pre-treatment and follow-up CECT or Gd-MRI was 160 days. Tumor arterial enhancement was measured at baseline and follow-up: (tumor attenuation/intensity on arterial phase – tumor attenuation/intensity on unenh! anced images)/(tumor attenuation/intensity on unenhanced images) x 100. Response was assessed according …
uMemristorToolbox: Open source framework to control memristors in Unity for ternary applications
2020
This paper presents uMemristorToolbox, a novel open source framework that reads and writes non-volatile ternary states to memristors. The Unity (C#) framework is a port of the open source Java project Memristor-Discovery and adds a closed-loop ternary memory controller to enable both PC and real-time embedded ternary applications. We validate the closed-loop ternary memory controller in an embedded system case study with 16 M+SDC Tungsten dopant memristors. We measure an average switching speed of 3 Hz, worst case energy usage of 1 μW per switch, 0.03% random write error and no decay in (non-volatile) state retention after 15 minutes. We conclude with observations and open questions when wo…
Singlet‐Contrast Magnetic Resonance Imaging: Unlocking Hyperpolarization with Metabolism
2020
Abstract Hyperpolarization‐enhanced magnetic resonance imaging can be used to study biomolecular processes in the body, but typically requires nuclei such as 13C, 15N, or 129Xe due to their long spin‐polarization lifetimes and the absence of a proton‐background signal from water and fat in the images. Here we present a novel type of 1H imaging, in which hyperpolarized spin order is locked in a nonmagnetic long‐lived correlated (singlet) state, and is only liberated for imaging by a specific biochemical reaction. In this work we produce hyperpolarized fumarate via chemical reaction of a precursor molecule with para‐enriched hydrogen gas, and the proton singlet order in fumarate is released a…
Role of apparent diffusion coefficient values in prostate diseases characterization on diffusion-weighted magnetic resonance imaging.
2019
BACKGROUND: To evaluate if normal and pathological prostate tissue can be distinguished by using apparent diffusion coefficient (ADC) values on magnetic resonance imaging (MRI) and to understand if it is possible to differentiate among pathological prostate tissues using ADC values.METHODS:Our population consisted in 81 patients (mean age 65.4 years) in which 84 suspicious areas were identified. Regions of interest were placed over suspicious areas, detected on MRI, and over areas with normal appearance, and ADC values were recorded. Statistical differences between ADC values of suspicious and normal areas were evaluated. Histopathological diagnosis, obtained from targeted biopsy using MRI-…
Neurochemical correlates of brain atrophy in fibromyalgia syndrome: a magnetic resonance spectroscopy and cortical thickness study
2020
(1) Background: Recently, a series of clinical neuroimaging studies on fibromyalgia (FM) have shown a reduction in cortical volume and abnormally high glutamate (Glu) and glutamate + glutamine (Glx) levels in regions associated with pain modulation. However, it remains unclear whether the volumetric decreases and increased Glu levels in FM are related each other. We hypothesized that higher Glu levels are related to decreases in cortical thickness (CT) and volume in FM patients. (2) Methods: Twelve females with FM and 12 matched healthy controls participated in a session of combined 3.0 Tesla structural magnetic resonance imaging (MRI) and single-voxel MR spectroscopy focused on the thalami…
Multi-subject fMRI analysis via combined independent component analysis and shift-invariant canonical polyadic decomposition
2014
Canonical polyadic decomposition (CPD) may face a local optimal problem when analyzing multi-subject fMRI data with inter-subject variability. Beckmann and Smith proposed a tensor PICA approach that incorporated an independence constraint to the spatial modality by combining CPD with ICA, and alleviated the problem of inter-subject spatial map (SM) variability.This study extends tensor PICA to incorporate additional inter-subject time course (TC) variability and to connect CPD and ICA in a new way. Assuming multiple subjects share common TCs but with different time delays, we accommodate subject-dependent TC delays into the CP model based on the idea of shift-invariant CP (SCP). We use ICA …
Gūžas un ceļa locītavu endoprotezēšanas operāciju izvērtējums (2009-2018) Traumatoloģijas un Ortopēdijas slimnīcā
2019
Mana diplomdarba mērķis ir kvantitatīvi novērtēt gūžas locītavu cementējamā, bezcementa, hibrīda un cervikokapitā tipa endoprotezēšanas operāciju skaitu, ceļa locītavu endoprotezēšanas operāciju, revīzijas operāciju skaitu, kā arī infekciju skarto pacientu skaitu, kas ir kā iemesls revīzijas operācijai un papildus pie katra atbilstošā endoprotēzes tipa kvantitatīvi atspoguļot vidējo pacienta ārstēšanās ilgumu slimnīcā. Pētījuma dati ņemti no TOS arhīva un atspoguļo endoprotezēšanas operāciju skaitu 10 gadu griezumā (2009. – 2018.gadam). Rezultātos kopumā 10 gadu griezumā TOS tika veiktas 18277 gūžas un ceļa locītavu endoprotezēšanas operācijas, ieskaitot revīziju operācijas. Primāro gūžas u…
Association of Dietary Patterns with MRI Markers of Hepatic Inflammation and Fibrosis in the MAST4HEALTH Study
2022
Whereas the etiology of non-alcoholic fatty liver disease (NAFLD) is complex, the role of nutrition as a causing and preventive factor is not fully explored. The aim of this study is to associate dietary patterns with magnetic resonance imaging (MRI) parameters in a European population (Greece, Italy, and Serbia) affected by NAFLD. For the first time, iron-corrected T1 (cT1), proton density fat fraction (PDFF), and the liver inflammation fibrosis score (LIF) were examined in relation to diet. A total of 97 obese patients with NAFLD from the MAST4HEALTH study were included in the analysis. A validated semi-quantitative food frequency questionnaire (FFQ) was used to assess the quality of diet…
Current status of phosphodiesterase inhibitors in the treatment of congestive heart failure.
1992
The phosphodiesterase inhibitors have been recognised as potent inotropic and vasodilating drugs. In acute congestive heart failure they increase cardiac output, decrease left pulmonary capillary wedge pressure, and reduce total peripheral resistance with an improvement in loading conditions of the failing heart. Their potency in reversal of symptoms of acute congestive heart failure is quite similar to, or even better than, treatment with intravenous catecholamines and sodium nitroprusside. In chronic congestive heart failure, however, these agents increase mortality and have deleterious effects in the outcome of patients with severe left ventricular dysfunction.