View clinical trials related to Magnetic Resonance Imaging.
Filter by:Cerebral venous thrombosis (CVT) is a rare disease, and with poor prognosis. Computed tomography (CT) andmagnetic resonance imaging (MRI) are the most commonly used image modalities for patients with non-specific neurologic symptoms. We are going to assess the accuracy of CT and MRI in the differential diagnosis of CVT and cerebral venous sinus thrombosis (CVST).
Recently, natural D-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using D-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. Our study try to evaluate the feasibility of dynamic glucose enhanced(DGE) magnetic resonance imaging（MRI）in brain tumor, which based on D-glucose weighted chemical exchange saturation transfer (gluceoCEST).
To investigate the cognitive decline after standard medical treatment without stenting in Asymptomatic Intracranial Stenosis patients and the underlying neural mechanism by fMRI.
Rationale: Chordomas and chondrosarcomas located in the axial skeleton are malignant neoplasms of bone. These tumors share the same clinical challenges, as the effect of the disease is more a function of their local aggressiveness than their tendency to metastasize (20% metastasize). The local aggressive behavior can cause debilitating morbidity and mortality by destruction of nearby located critical neurovascular structures. Imaging has, in addition to histopathology, a role in diagnosis and in guiding (neo)adjuvant and definitive treatment. Despite the low sensitivity to radiotherapy, proton radiotherapy has been successfully used as an adjunct to resection or as definitive treatment for aggressive chordomas and chondrosarcomas, making it a standard indication for proton therapy in the Netherlands. Chordomas and chondrosarcomas consist, especially after previous therapy, of non-viable and viable tumor components. Identification of these viable components by functional imaging is important to determine the effect of previous therapy, as change in total tumor volume occurs more than 200 days after change of functional imaging parameters. Objective: The main objective of this study is to determine if functional MRI parameters change within 6 months, and earlier than volumetric changes after start of proton beam therapy. This would allow timely differentiation between affected and unaffected (viable) tumor components, which can be used for therapy adjustment. Secondary objectives: Determine which set of parameters (PET-CT and secondary MRI) can predict clinical outcome (tumor specific mortality, development of metastases, morbidity secondary to tumor activity and morbidity secondary to treatment); determine what type of imaging can accurately identify viable tumor nodules relative to critical anatomical structures; improving understanding of relevance of changing imaging parameters by correlating these with resected tumor. Study design: Prospective cohort study Study population: LUMC patients diagnosed with primary or recurrent chordoma or chondrosarcoma in the axial skeleton. A number of 20 new patients per year is expected. Main study parameters: Volumetric and functional MR imaging parameters including permeability parameters. Secondary parameters are generated by PET-CT (SUV, MTV and TLG), MR (perfusion, permeability and diffusion), therapy (proton beam dose mapping, surgery) and clinical outcome. End points are disease specific survival, progression free survival (including development of metastases), side effects of treatment, and functional outcome (see CRF). In patients who are treated with surgical resection following neo-adjuvant therapy, the surgical specimen will be correlated with imaging findings. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Treatment and clinical management will not be affected in this study, thus the additional burden, risks, and benefits associated with participation in this study are minimal. Two extra MRI and one PET-CT examination will be planned during proton therapy.
The investigators hypothesize that preventive VT substrate ablation in patients with chronic ICM, previously selected based on imaging criteria (BZC mass) for their likely high arrhythmic risk, is safe and effective in preventing clinical VT events.
Up to now, multiplanar reconstruction (MPR) has been widely used to detect the neurovascular compressions (NVC) on the patients with hemifacial spasm (HFS). However, due to lack of stereoscopic vision, this traditional method sometimes can not meet the requirement on identifying the details of NVC, especially when the aberrant vessels turn out to be veins not arteries. The three dimensional analytic techniques, such as curved planar reconstruction (CPR) and magnetic resonance virtual endoscopy (MRVE), may be helpful to improve the sensitivity and specificity on the demonstration of NVC with stereo and dynamic views, so as to assist the design of the surgical plan. Furthermore, the frequent finding of NVC on MRI studies of asymptomatic patients incited the creation of several strict criteria for the imaging diagnosis of NVC: the vessel must cross perpendicular to the long axis of the nerve, the nerve must be deviated or indented at the root entry zoon (REZ) by the vessel. Alternatively, morphological measurement of the nerve may correlate with the severity of facial spasm due to atrophy of the nerve in most cases of HFS, and is likely secondary to the micro-structural abnormalities, such as axonal loss, demyelination, collagen deposition, etc. In this study, cross-sectional area (CSA) and volume (V) of the cisternal facial nerve will be assessed to determine whether it can be a useful biomarker for predicting the degree of HFS.
Positron Emission Tomography (PET) provides a valuable tool for the diagnosis and staging of liver fibrosis. Activation of hepatic stellate cell (HSC) is a key link in the pathophysiological development of liver fibrosis. In human liver tissue, fibroblast activation protein (FAP) was only expressed in active HSCs and fibroblasts, but not in static HSCs. Therefore, FAP has become an excellent target for diagnosis and treatment of liver fibrosis. Recently, radionuclide-labeled fibroblast activation protein inhibitors (FAPI) as a new novel positron tracer has shown to be effective to detect various cancers. In this prospective study, the investigators will use the most advanced imaging equipments, integrated PET/MR, and PET/CT with gallium-68 (68Ga) -FAPI to image patients with or suspected of liver fibrosis, the aim is to explore the value of 68Ga-FAPI hybrid PET/MR and PET/CT in liver fibrosis.
Using Multi-tracer to early diagnosis of therapy-associated cardiotoxicity using multimodality PET/MRI.
Diffusion tensor imaging (DTI) is a non-invasive MRI technique offering a functional approach that provides morphological information about the microstructures of the nerve roots. DTI is a widely used neuroimaging technique and is a current topic of research in the field of peripheral nerve imaging.The aim of the study is to determine the prognostic quality of the DTI parameters to predict the therapeutic evolution of patients with lumbar radiculalgia at 6 months.
Today in elderly tooth loss and loss of oral function is widespread, but it is an underexplored modifiable risk factor potentially contributing to the development of dementia. In this interventional study a "cause-effect" relationship between mastication and cognition in humans will be investigated. A total of eighty (80) participants, 65-80 years of age, indicated for prosthodontic rehabilitation will be randomly assigned to either the experimental or the control group. Participants will be randomized into two different groups, measurements are going to be conducted before and after prosthetic rehabilitation. The difference between the two groups is that the control group are going to do two measurements before undergoing the rehabilitation, this to control for the test-re-test effect. The aim with this study is to determine if the rehabilitation of chewing function will cause changes in the neurocognitive assessments of episodic memory and learning.