Search results for "mri"
showing 10 items of 733 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…
Femoro-acetabular impingement. Classification, diagnosis and treatment.
2010
Introduction: The femoro-acetabular impingement (FAI) is the result of a number of congenital or acquired pathologies of the hip and it has as main pathogenetic element an abnormal contact between the two joint components (acetabulum and proximal femoral epiphysis). Mainly male young adults, often athletes, are affected because of the repetition of gestures responsible for the conflict in these subjects. Classification: FAI has specific clinical and radiological characteristics and it can be classified into three types: 1. CAM type (femoral). 2. PINCER type (acetabular). 3. CAM-PINCER mixed-type. Diagnosis: It is based on medical hystory (young and active patients, diseases or previous hip …
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…
Size-isolation of superparamagnetic iron oxide nanoparticles improves MRI, MPI and hyperthermia performance.
2020
Journal of nanobiotechnology 18, 22 (2020). doi:10.1186/s12951-020-0580-1
Is spectral domain optical coherence tomography useful in improving the contour line with the heidelberg retina tomograph?
2012
Purpose: To compare the measurements of the optic disc in glaucoma patients and glaucoma suspects with spectral domain optical coherence tomography (SD-OCT) and confocal scanning laser ophthalmoscopy (HRT) before and after adjustment of the contour line with the help of the OCT.Methods: In 109 consecutive patients (109 eyes), optic disc parameters were compared prospectively between the 2 devices before and after adjustment of the optic disc area (ODA) on the HRT3 with ODA obtained with the Cirrus SD-OCT as a reference. Intraclass correlation coefficients (ICC) and the 95% limits of agreement (LoA) with Bland-Altman plots were used to compare the agreement of the pre and post-adjustment mea…
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-…
Diagnostic performance and reproducibility of T2w based and diffusion weighted imaging (DWI) based PI-RADSv2 lexicon descriptors for prostate MRI.
2017
To examine the diagnostic performance of PI-RADSv2 T2w and diffusion weighted imaging (DWI) based lexicon descriptors, inter-observer agreement for descriptor assignment and diagnostic accuracy of the PI-RADSv2 assessment categories for multiparametric prostate MRI.176 lesions in 79 consecutive patients are analyzed, lesions are histopathologically verified by MRI-ultrasound fusion biopsy. All lesions are rated according to the PI-RADSv2 lexicon, descriptors for T2w and DWI sequences and resulting assessment categories are assigned by two independent blinded radiologists. We perform receiver-operating-characteristic analysis using the assessment categories. To analyze inter-observer agreeme…
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…