Search results for " gadolinium"
showing 10 items of 40 documents
Gadolinium perturbs expression of skeletogenic genes, calcium uptake and larval development in phylogenetically distant sea urchin species
2018
Chelates of Gadolinium (Gd), a lanthanide metal, are employed as contrast agents for magnetic resonance imaging and are released into the aquatic environment where they are an emerging contaminant. We studied the effects of environmentally relevant Gd concentrations on the development of two phylogenetically and geographically distant sea urchin species: the Mediterranean Paracentrotus lividus and the Australian Heliocidaris tuberculata. We found a general delay of embryo development at 24 h post-fertilization, and a strong inhibition of skeleton growth at 48 h. Total Gd and Ca content in the larvae showed a time- and concentration-dependent increase in Gd, in parallel with a reduction in C…
Left ventricular Myocardial dysfunction in arrhythmogenic cardiomyopathy with left ventricular involvement: A door to improving diagnosis.
2018
[EN] Background: Diagnostic Task Force Criteria (TFC) for arrhythmogenic cardiomyopathy (AC) exhibit poor performance for left dominant forms. TFC only include right ventricular (RV) dysfunction (akinesia, dyssynchrony, volumes and ejection fraction). Moreover, cardiac magnetic resonance imaging (CMRI) assessment of left ventricular (LV) dyssynchrony has hitherto not been described. Thus, we aimed to comprehensively characterize LVCMRI behavior in AC patients. Methods: Thirty-five AC patients with LV involvement and twenty-three non-affected family members (controls) were enrolled. Feature-tracking analysis was applied to cine CMRI to assess LV ejection fraction (LVEF), LV end-systolic and …
Abortion induces reactivation of inflammation in relapsing-remitting multiple sclerosis
2018
ObjectiveTo investigate clinical and radiological outcomes of women with relapsing-remitting multiple sclerosis (RRMS) undergoing abortion.MethodsAn independent, multicentre retrospective study was conducted collecting data from eight Italian MS centres. We compared the preconception and postabortion annualised relapse rate (ARR) and number of Gadolinium enhancing (Gd+) lesions, by analyses of covariance. Variables associated with postabortion clinical and MRI activity were investigated using Poisson regression models; each abortion was considered as a statistical unit.ResultsFrom 1995 to 2017, we observed 188 abortions (17 elective) in 153 women with RRMS. Abortions occurred after a mean t…
Dosimetry to Electron Spin Resonance (ESR) using organic compounds (alanine and ammonium tartrate) for mixed neutron-gamma fields
2015
Alongside with the development of Neutron Capture Therapy (NCT) and the use of thermal neutrons for radiotherapeutic purposes, many efforts have been devoted to the characterization of the beam in order to optimize therapy procedures. Reliable dose measurements should be able to determine the various (neutrons and photonic) components of the mixed beam usually employed for therapy. This paper studies the effect of additives such as Boric and Gadolinium nuclei on the sensitivity of neutron organic (alanine and ammonium tartrate) dosimeters analyzed through Electron Spin Resonance (ESR) technique. These dosimeters were exposed to a mixed (neutron-gamma) field mainly composed of thermal neutro…
Toxicological Impact of Rare Earth Elements (REEs) on the Reproduction and Development of Aquatic Organisms Using Sea Urchins as Biological Models
2022
The growing presence of lanthanides in the environment has drawn the attention of the scientific community on their safety and toxicity. The sources of lanthanides in the environment include diagnostic medicine, electronic devices, permanent magnets, etc. Their exponential use and the poor management of waste disposal raise serious concerns about the quality and safety of the ecosystems at a global level. This review focused on the impact of lanthanides in marine organisms on reproductive fitness, fertilization and embryonic development, using the sea urchin as a biological model system. Scientific evidence shows that exposure to lanthanides triggers a wide variety of toxic insults, includi…
Monte Carlo simulation of the response of ESR dosimeters added with gadolinium exposed to thermal, epithermal and fast neutrons
2009
Abstract Monte Carlo numerical calculations of the response of alanine and ammonium tartrate ESR (electron spin resonance) dosimeters exposed to neutron fields with different energy spectra are reported. Results have been obtained for various gadolinium concentrations inside the dosimeters. Furthermore, in order to simulate the in-phantom response we have carried out calculations by varying the depth of the dosimeter. We have found that a large enhancement is obtained for thermal neutrons, because of the very high capture cross section of gadolinium to thermal neutrons. A good enhancement was obtained for epithermal neutrons, whereas the sensitivity improvement in the case of fast neutron i…
Computed tomography detects changes in contrast agent diffusion after collagen cross-linking typical to natural aging of articular cartilage
2011
SummaryObjectiveThe effect of threose-induced collagen cross-linking on the mechanical and diffusive properties of cartilage was investigated in vitro. In particular, we investigated the potential of Contrast Enhanced Computed Tomography (CECT) to detect changes in articular cartilage after increased collagen cross-linking, which is an age-related phenomenon.MethodsOsteochondral plugs (Ø=6.0mm, n=28) were prepared from intact bovine patellae (n=7). Two of the four adjacent samples, prepared from each patella, were treated with threose to increase the collagen cross-linking, while the other two specimen served as paired controls. One sample pair was mechanically tested and then mechanically …
Association between radiography-based subchondral bone structure and MRI-based cartilage composition in postmenopausal women with mild osteoarthritis
2016
Summary Objective Our aim was to investigate the relation between radiograph-based subchondral bone structure and cartilage composition assessed with delayed gadolinium enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T 2 relaxation time. Design Ninety-three postmenopausal women (Kellgren–Lawrence grade 0: n = 13, 1: n = 26, 2: n = 54) were included. Radiograph-based bone structure was assessed using entropy of the Laplacian-based image ( E Lap ) and local binary patterns ( E LBP ), homogeneity indices of the local angles (HI Angles,mean , HI Angles,Perp , HI Angles,Paral ), and horizontal (FD Hor ) and vertical fractal dimensions (FD Ver ). Mean dGEMRIC index and T 2 relax…
Comparison of Nonclassic and Classic Phenotype of Hypertrophic Cardiomyopathy Focused on Prognostic Cardiac Magnetic Resonance Parameters: A Single-C…
2022
Patients with nonclassic phenotypes (NCP)—more advanced stages of hypertrophic cardiomyopathy (HCM)—constitute an intriguing and heterogeneous group that is difficult to diagnose, risk-stratify, and treat, and often neglected in research projects. We aimed to compare cardiac magnetic resonance (CMR) parameters in NCP versus classic phenotypes (CP) of HCM with special emphasis given to the parameters of established and potential prognostic importance, including numerous variables not used in everyday clinical practice. The CMR studies of 88 patients performed from 2011 to 2019 were postprocessed according to the study protocol to obtain standard and non-standard parameters. In NCP, the late …
A 3D Network Based Shape Prior for Automatic Myocardial Disease Segmentation in Delayed-Enhancement MRI
2021
Abstract Objectives: In this work, a new deep learning model for relevant myocardial infarction segmentation from Late Gadolinium Enhancement (LGE)-MRI is proposed. Moreover, our novel segmentation method aims to detect microvascular-obstructed regions accurately. Material and methods: We first segment the anatomical structures, i.e., the left ventricular cavity and the myocardium, to achieve a preliminary segmentation. Then, a shape prior based framework that fuses the 3D U-Net architecture with 3D Autoencoder segmentation framework to constrain the segmentation process of pathological tissues is applied. Results: The proposed network reached outstanding myocardial segmentation compared wi…