View clinical trials related to Magnetic Resonance Imaging.
Filter by:Optimizing the MRI protocol in acute ischemic stroke remains a challenging issue. In this field, susceptibility-weighted sequences have proved their superiority over T2. Besides the strengthened susceptibility effect, enhanced susceptibility-weighted angiography (eSWAN) sequence provides also a time-of-flight (TOF) effect, allowing the exploration of the intracranial arterial circulation. The objective of this study is to compare eSWAN and 3D TOF, considered as the reference, in the detection of arterial occlusion in acute stroke.
Patients with osteoarthritis of the knee undergo visible joint changes in radiology and Magnetic resonance imaging (MRI) tests, but also clinically and histologically. The area of greatest change is at the subchondral/cartilage bone junction. Investigators will determine the association between preoperative clinical evaluation (IKDC and Womac scores), radiological classifications and histopathology. In addition, the role of inflammation in the pathogenesis of osteoarthritis is being given major interest, and inflammation is closely linked with vascularization. It was recently demonstrated that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could identify the subchondral bone marrow vascularization changes occurring in osteoarthritis in animals. These changes appeared before cartilage lesions were visible and were correlated with osteoarthritis severity. Thus the opportunity to obtain an objective assessment of bone vascularization in non-invasive conditions in humans might help better understanding osteoarthritis pathophysiology and finding new biomarkers. Investigators hypothesized that, as in animals, DCE-MRI has the ability to identify subchondral bone marrow vascularization changes in human osteoarthritis.
The aim of this study is to determine if and how the "Probiotic Product" affects functional brain responses in healthy subjects during an emotional- and arithmetic stress task, respectively and in terms of microbe-brain-gut interactions.
To investigate the treatment effect of theta-burst transcranial magnetic stimulation on Alzheimer patients, and the underlying neural mechanism by MRI.
The study was conducted to gain knowledge about a new dose of a diagnostic drug that is used for contrast-enhanced Magnetic Resonance Imaging (MRI) of the human central nervous system (CNS). MRI can visualize the anatomy of the body and is used to detect medical conditions. Diagnostic drugs like gadobutrol and gadoterate contain an element called gadolinium that is applied to improve the analysability of MRI-images. The purpose of this study was to examine if contrast-enhanced MRI using a reduced dose of the gadolinium-based contrast agent gadobutrol delivers images of similar quality to those obtained when a full dose of the gadolinium-based contrast agent gadoterate was used.
This study is an exploratory study aiming to collect data on sensitivity and positive predictive value of IOP-enhanced (MPB-1523) MRI compared to dynamic multiphase MDCT for the detection of HCC.
The objective of the study is to assess the dose dependent changes in MRI signal intensity (SI) in liver after IOP Injection intravenous administration in healthy volunteers.
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.