View clinical trials related to Magnetic Resonance Imaging.
Filter by:Gadolinium-enhanced magnetic resonance imaging (MRI) is currently the imaging gold standard to detect active inflammatory lesions in multiple sclerosis (MS) patients. The sensitivity of enhanced MRI to detect active lesions may vary according to the acquisition strategy used (e.g., delay between injection and image acquisition, contrast dose, field strength, and frequency of MRI sampling). Selection of the most appropriate T1-weighted sequence after contrast injection may also influence sensitivity. Several clinical studies performed at 1.5 Tesla have shown that conventional 2D spin-echo (SE) sequences perform better than gradient recalled-echo (GRE) sequences for depicting active MS lesions after gadolinium injection. As relates to MS, 3.0 Tesla systems offer some advantages over lower field strengths, such as higher detection rates for T2 and gadolinium-enhancing brain lesions, an important capability for diagnosing and monitoring MS patients. Recent studies have shown that at 3 Tesla, 3D GRE or 3D fast SE sequences provide higher detection rates for gadolinium-enhancing MS lesions, especially smaller ones, than standard 2D SE, and better suppress artefacts related to vascular pulsation. However, the comparison of the performance of 3D GRE versus 3D SE sequences has not been investigated yet. Objectives To compare the sensitivity of enhancing multiple sclerosis (MS) lesions in gadolinium-enhanced 3D T1-weighted gradient-echo (GRE) and turbo-spin-echo (TSE) sequences.
Knowledge of the evolution of multiple sclerosis (MS) and its long-term prognostic factors is essential to guide the therapeutic management. However, it remains partial and concerns above all data collected during the first years of the disease. The evolution towards disability can only be assessed after a follow-up of more than 10 years and does not depend solely on the initial inflammatory activity of the disease. We propose to realize a standardized clinical assessment, an optical coherence tomography (OCT) and a cerebral MRI 15 years after the first clinical manifestation of the disease. Clinical and paraclinical assessment will consist in the realization of additional MRI sequences in order to obtain more precise information on cerebral lesions (unconventional parameters). Optical coherence tomography (new generation device) will also be performed on both eyes to describe the thickness of the different layers of the retina. A clinical evaluation will be performed with the Expanded Disability Status Scale (EDSS). This study aims: 1. to describe the current clinical situation of patients (e.g. percentage of patients with moderate or severe disability) 2. to explore the associations between MRI parameters, those measured with OCT and clinical characteristics (disability) 3. to explore clinical and paraclinical prognostic factors of pejorative evolution (disability, severe cerebral atrophy, etc.)
Ischemic strokes are the first cause of handicap in adult people, the second cause of dementia and the third cause of death in France. Brain Magnetic Resonance (MR) initial assessment is mandatory to get the right diagnosis, to exclude hemorrhagic lesions and to determine the best treatment. The conventional diffusion weighted imaging sequence is used to establish the diagnosis and to estimate the volume of ischemic lesions. The perfusion weighted imaging sequences are also used to assess the diffusion-perfusion mismatch which is supposed to be the ischemic penumbra corresponding to territories that could be saved with appropriate treatments. IntraVoxel Incoherent Motion (IVIM) is a multi-b diffusion sequence which allows to extract four quantitative variables (D, D*, f, ADC) related to the true molecular diffusion and correlated to the microvascular perfusion. It's a quick sequence with no need of contrast injection and allowing a perfect coregistration with the true diffusion. It has been validated in many pathologies but not in acute strokes. The feasibility of this sequence in acute ischemic strokes has already been assessed with interesting results. The study aims to assess the correlation between the quantitative values of IVIM at initial MR exam and the modified Rankin Scale (mRS) score 3 months after an acute ischemic stroke.
Pain is complex phenomenon misunderstood in spite of medical progress and neurosciences. That's why the relief of chronic pain is only partial for a lot of infection as arthrosis, chronic back pain, headaches or neuropathic pain. Certain situations bring to relive pain sensation. Investigators were interested to former burned. They wonder about somatic memory and unconscious of acute.
The goals of this research will be to define some of the mechanisms underlying the progression and complications of heart failure (HF) with preserved left ventricular ejection fraction (HFPEF) Aim 1: to evaluate the differences in cardiac structure, function and fibrosis markers through the spectrum of HF stages in order to deepen the understanding of the pathophysiology driving HF progression. Aim 2: to define the mechanisms by which HF risk factors, such as hypertension, diabetes, obesity, and renal insufficiency, interact with age to increase HF risk, and to evaluate the role of precipitating factors such as myocardial ischemia, atrial fibrillation in HFPEF. Aim 3: to determine prognostic factors in HFPEF patients, by following these patients over time. Accordingly the investigators will correlate baseline data (echocardiographic, MRI or biomarkers) with incident cardiovascular events and determine whether these measures provide incremental prognostic information beyond clinical characteristics.
Axial Spondyloarthritis (SpA) is a kind of inflammatory arthritis which includes ankylosing spondylitis. Common symptoms of axial SpA are inflammatory back pain, morning stiffness, peripheral arthritis, enthesitis. Controlling aforementioned symptoms are one of the goal in treatment, and another goal is preventing bony ankylosis of axial skeleton such as spine. Ankylosis can limit range of motion and lower the quality of life. Non-steroidal antiinflammatory drug (NSAID) and Tumor necrosis factor (TNF)-a inhibitor are the current treatment options for axial SpA. These medications can improve pain and stiffness of axial SpA patients, however preventing bony ankylosis is not proven. Current study showed attenuating inflammation at early stage could prevent further bony destruction and ankylosis in axial SpA. Present study is designed to discover the therapeutic effect of NSAID whether NSAID could recover the early inflammatory bony change (bone marrow edema at MRI) and prevent further bony change.
Crying is the primary signaling strategy available to the human newborn for eliciting parental care. Yet, the investigators only have superficial understanding of the information carried by cries, and how this information is perceived by parents. Using modern tools of sound processing and functional Magnetic Resonance Imaging (fMRI) experiment, this study aims to investigate cry-induced brain activation in adult depending on the cry's acoustic properties expressing various degrees of stress and distress levels. For that, Adults will be tested inside a fMRI magnet to determine their brain activations elicited by different babies cries according to whether the cry was evoked in a pain situation or not. The cerebral activity will be investigated in relation to acoustic features of cries (e.g. with pitch and/or roughness variations). To test if the gender or parentally of adult listeners influence their perceptions and brain responses, the task will be applied to 2 different groups (men and women not-parents). The hypothesis is that the brain of adult listeners will be able to discriminate adequately the intensity of the pain mediated by the cries. This process should involve brain areas such as the insular and the orbito frontal cortex that are known to participate in the integration of pain intensity and pain controls. The experiment should also determine which one of the acoustic features is able to transmit pain and to recruit brain areas involved in pain processes.
Background: Detection of coronary artery disease (CAD) is important due to its high prevalence and its medical and economic implications. Purpose: A systematic review of the diagnostic performance of stress echocardiography (Echo), SPECT, cardiac magnetic resonance (CMR), CT Perfusion (CTP) and PET versus invasive coronary angiography (ICA) or fractional flow reserve (FFR) using hierarchical summary ROC (HSROC) methods. Data Sources: MEDLINE, EMBASE and SCOPUS for literature published in English or Spanish from January 1970 to December 2015. Study Selection: For inclusion, studies had to meet the Cochrane guidelines, had to evaluate the sensitivity and specificity methods, and use ICA and/or FFR. Only those studies with STARD methodology ≥60% were included. Data Extraction: Ten investigators extracted patient and study characteristics and 4 resolved any disagreements.
Studies that will be carried out on healthy volunteers will have as main objective the development and optimization of the parameters of sequences or the design of the paradigms of stimulation in order to optimize the quality and the relevance of the images realized taking in Taking account of anatomical, functional or metabolic parameters, or integrating new approaches resulting from technical evolutions
The main objective of the studies that will be carried out on volunteer patients who have given their consent will be the development and optimization of the sequence parameters or the design of the stimulation paradigms in order to optimize the quality and Relevance of the images realized taking into account anatomical, functional or metabolic parameters. These adjustments will be carried out without interfering with the management of voluntary patients