Thanks to the development of modern neuroimaging methods, it is now possible to better study the brain in all its complexity in a non-invasive way. Thanks to these different modalities, the new Magnetic Resonance Imaging (MRI) techniques allow to measure the functioning of the resting brain, the cellular edemas, the quantity of iron, as well as the modification resulting from the realization of various cognitive tasks, to study with precision its anatomy as well as connections between neurons. These multimodal MRI sequences also make it possible to perform longitudinal measurements and also to detect cerebral changes induced by a specific treatment. As part of this project, we will perform multimodal MRI before and after gene therapy in different pathologies to better characterize and understand the effect of these new therapeutic strategies on the brain (sickle cell disease, neurodegenerative diseases, mitochondrial or Friedreich ataxia).All these projects are related to the projects supported by the DIM Gene Therapy. Our team, “Image at Imagine”, is an IHU MRI platform where patients involved in IHU research projects can benefit from advanced brain imaging and ad-hoc image processing.