Clinical Research Directory

Carbon Dioxide Administration and Brain Waste Clearance

The current study tests whether different exposures to carbon dioxide (CO2) can safely result in the increased movement of proteins from the brain into the blood. The investigators believe that this would be a proxy for the brain clearing waste products more effectively. The current study will use a counter-balanced design, in which individuals with and without a history of traumatic brain injury (TBI) will receive different levels of CO2 (targeted changes of approximately 5 or 10 mmHG in end-tidal CO2) approximately one week apart. The counter-balanced design means that each participant receives a single dose of CO2 at each visit, and different doses of CO2 at each visit. The order in which participants receive the dose is randomized, and the participant will not be informed of the dose.

New Simulation Care Pathway for Paediatric MRI Preparation

Magnetic resonance imaging (MRI) is a common imaging procedure that is safe and non-invasive, as it relies on the use of different magnetic fields. It is the gold standard examination for a wide range of pathologies. However, it has many disadvantages, including the repetitive noise produced by the coils during image acquisition sequences, which can cause discomfort. The noise level often exceeds 100 dB, while the noise exposure limit for workers is set at 87 dB. There is no regulatory limit for patients. Although it is relatively loud and quite unpleasant, this noise is not harmful to health and does not amplify, contrary to the perception that one may have in the tunnel. Noise-cancelling headphones and earbuds are strongly recommended for patients to reduce any discomfort that may result. In practice, the imaging department requires all patients to wear hearing protection. Other disadvantages of MRI include confinement in a tunnel and the need to remain completely immobile for approximately six sequences, each of 2 to 5 minutes in duration. This can be problematic, particularly for patients suffering from pain or respiratory failure, or for agitated individuals who find it difficult to remain motionless in a lying position for long periods of time. These various issues are particularly relevant in the paediatric population, for whom MRI is the preferred imaging technique due to its safety in terms of radiation exposure. The specific characteristics of this population require more complex patient management due to the particular constraints of MRI. Acceptance of the following four points appears to be key to its successful implementation: lying down, with the head in a tunnel, intense and repeated noises, and strict immobility for at least 30 minutes. Without these conditions, the images recorded will not provide reliable results that can be used for diagnosis. To meet these constraints, at Nantes University Hospital, general anaesthesia was routinely administered to children aged 3 to 6 until September 2023. This ensures a 100% success rate for the examination, but it is not a trivial procedure for the child and is stressful for their parents. Since then, a light sedation protocol has been offered as part of the care pathway. This involves the child taking medication one hour and then thirty minutes before the MRI scan to calm them down until they fall asleep. Unfortunately, access to this MRI under light sedation or general anaesthesia complicates the appointment booking process, as it requires the presence of a medical team during dedicated shifts. MRI scans under light sedation are scheduled for three slots per week. At the end of 2025, the waiting time was four months for light sedation and six months for general anaesthesia. In order to improve and speed up the care of children who need to perform an MRI scan, a specific consultation with an immersive four-module programme has been designed at Nantes University Hospital with the aim of optimising the chances of success of the examination without general anaesthesia or sedation, thereby: * Reduce waiting times for appointments, and thus reduce the period of stress for parents awaiting a diagnosis for their child. * Reduce the time required for the examination. Indeed, an examination under light sedation considerably lengthens the treatment time, with a sedation onset time of approximately 1.5 hours. * Increasing the success rate of MRI scans under light sedation following failure without sedation. This innovative approach is based on an immersive experience in the form of a course consisting of four modules designed to help children practise four areas that can be challenging for them (immersion in a tunnel, loud noise, the constraints of specific equipment, and immobility). These modules are themed around the marine world, in line with the already approved paediatric radiology programme. It will be offered to children aged 3 to 6 with no cognitive or behavioural disorders. The modules will be installed in a paediatric consultation room and will be used for half a day each month. When not needed, they'll be put away so the room can be used for consultations. The aim of our pilot study is to assess the impact of this immersive journey on the success of an MRI scan without general anaesthesia or sedation.

Internet-Based Cognitive Behavioral Therapy for MRI-Related Anxiety

The aim of the study is to investigate whether internet-based cognitive behavioural therapy (iCBT) can help patients who have difficulty undergoing magnetic resonance imaging (MRI). The main question to be answered is \- Can patients undergo MRI with less anxiety using iCBT? The patients will undergo a four-week treatment that includes information about MRI, anxiety management, relaxation and retention. The end goal is to simulate an MRI scan in a mock scanner where participants can report their anxiety. Half of the participants will be randomized to receive the treatment before (intervention group) the simulated MRI scan and half will receive the treatment after the simulated MRI scan (control group). Up to 60 patients will be included plus some pilot patients.

Interest of Magnetic Resonance Imaging in the Diagnosis of Upper Urinary Tract Invasive Tumours

Upper urinary tract invasive cancer magnetic resonance imaging diagnosis

Acute Effects of SGLT2 Inhibitor on Kidney Allograft Oxygen Tension

The goal of this clinical trial is to investigate if a single dose of oral SGLT2i, (50 mg Jardiance) will change oxygen tension in the kidney transplant. The main questions it aims to answer are: * Does a single dose of oral SGLT2i (50 mg Jardiance) change oxygen tension in the kidney transplant cortex and medulla, estimated by magnetic resonance imaging? * Does a single dose of oral SGLT2i (50 mg Jardiance) change kidney transplant cortical and medullary perfusion? * Does a single dose of oral SGLT2i (50 mg Jardiance) change kidney transplant artery blood flow? * Does a single dose of oral SGLT2i (50 mg Jardiance) change blood glucoses, blood pressure and heart rate? Researchers will compare a single dose of oral SGLT2i (50 mg Jardiance) to a placebo (a look-alike substance that contains no drug) to see if a single dose of oral SGLT2i (50 mg Jardiance) changes oxygen tension in the kidney transplant. Kidney transplant recipients with out diabetes will: * Meet for two intervention days. * A single dose of oral SGLT2i (50 mg Jardiance) or placebo will be given in random order, separated by at least 2 week washout period, the experiment will be repeated with the opposite treatment. * Kidney cortex oxygenation, and blood flow in different compartments of the kidney transplant, is estimated by blood-oxygen-dependent level magnetic resonance imaging (BOLD-MRI). Patients are evaluated by routine clinical examination and routine biochemical measures for kidney transplant patients.

Using Cardiac MRI to Predict Outcomes in Patients With STEMI

This prospective, multicenter observational study aims to evaluate the prognostic value of a comprehensive set of cardiac magnetic resonance (CMR) imaging parameters in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). The study integrates advanced artificial intelligence (AI) techniques to extract and analyze high-dimensional imaging features from multiple CMR sequences-including cine, strain mapping, and functional sequences-going beyond traditional measures such as infarct size or microvascular obstruction. The primary objective is to identify novel prognostic markers from routinely acquired CMR images that reflect myocardial structure, function, and mechanical deformation (strain), and to assess their association with long-term clinical outcomes. In addition to standard parameters, the study includes a detailed evaluation of left and right ventricular systolic and diastolic volumes, ejection fractions, and biventricular strain components (including longitudinal, circumferential, and radial strain), as well as left and right atrial volumes, emptying fractions, and reservoir/conduit/booster strain indices. Approximately 1000 STEMI patients will undergo CMR scanning within one week after PCI. The imaging data will be subjected to AI-based feature extraction and dimensionality reduction algorithms to uncover latent patterns associated with adverse outcomes. Patients will be followed for up to three years for the occurrence of major adverse cardiovascular events (MACE), including cardiovascular death, recurrent myocardial infarction, and heart failure hospitalization. The central hypothesis is that comprehensive CMR functional and strain-derived parameters, when analyzed using AI-driven models, offer independent and incremental prognostic value beyond conventional clinical risk factors. This study seeks to establish a data-driven, multimodal imaging framework for personalized risk stratification in STEMI patients, potentially enabling more precise post-infarction management strategies. No investigational treatment is involved. All imaging and clinical data are collected as part of routine care and analyzed retrospectively for outcome prediction.

Comparison of ultraSound, Abbreviated MRI witH and Without HBP aS mOdalities for HCC suRveillance in patienTs With High Risk

Active surveillance in high-risk hepatocellular carcinoma (HCC) populations enables early detection of tumors. The currently recommended monitoring protocol involves biannual serum alpha-fetoprotein (AFP) testing combined with liver ultrasound (US) examinations. However, conventional US demonstrates limited sensitivity in detecting early-stage HCC lesions. MRI demonstrates high sensitivity in monitoring cirrhotic patients, but prolonged scanning time limits its routine clinical application. Several abbreviated MRI protocols have been developed for HCC detection, aiming to reduce acquisition time while improving early-stage HCC diagnostic accuracy. The main question this clinical trial aims to answer is: Can non-contrast abbreviated MRI (NC-AMRI) and enhanced abbreviated MRI (E-AMRI) detect more early-stage HCC lesions compared to US-based screening? Researchers will randomly divide the participants into three groups in a 1:1:1 ratio, with different surveillance strategies, focused on early HCC detection rates.

Maternal Cardiovascular Adaption to Pregnancy in IVF Patients Following Frozen Embryo Transfer (FET)

Aim of the study is to explore the effect of a lacking corpus luteum on maternal cardiovascular and metabolic adaption to pregnancy by the use of magnetic resonance imaging (MRI).

Multimodal Image Technologies Investigate the Role and Mechanism of Probiotics in Improving RBD with Parkinson's Disease

Rapid eye movement sleep behavior disorder (RBD) is important non-movement feature, and also the important risk factor of Parkinson's disease (PD). In our previous work, we found that the movement features and RBD of PD patients improved after taking probiotics. The later was not reported before and the mechanism not clear. To investigate its role and mechanism, we plan to enroll patients of PD-RBD, idiopathic RBD, and healthy control, collect data of multimodal image technology before and after probiotic treatment，including resting state functional MRI，1H-MRS，123I-MIBG; analyze these data with clinical features, including UPDRS -III score, RBD-HK score , as well as the bacteria abundance and level of glutamate，GABA in blood and stool. Then, construct PD mouse model by fecal transplantation of PD patient, give or not give mouse probiotics treatment, and detect the level of glutamate, GABA, and so on, as well as α-synuclein of each brain area of each group, to explore the role and mechanism of probiotics in improving RBD and movement disorder of PD.