Development of Diffusion MRI and Tractography Technique for the Detection of Nerve Lesions in Brachial Plexus Injuries

Inclusion Criteria: * Patients aged 14 to 30 years * Consulted by the Orthopedics Department at Armand Trousseau Hospital * Diagnosed and monitored by Armand Trousseau Hospital for obstetrical brachial plexus palsy (OBBP) * Having a single, unoperated lesion (lesions are very different and only exceptionally affect all the roots bilaterally). * Not suffering from bone or neurological pathology unrelated to OBP * Patients affiliated with or entitled to a social security scheme * Patients who have received informed information and have signed, with the investigator, a consent form to participate in the study * Parents/legal guardians who have received informed information and have co-signed, with the investigator, a consent form to participate in the study, for minor patients Exclusion Criteria: * History of rheumatoid pathologies, constitutional bone diseases, past or current pathologies affecting the arm or neck unrelated to the obstetric brachial plexus, any history of neoplasia or radiographic appearance consistent with a neoplastic fracture * Current pregnancy * Inability to perform the MRI examination (presence of a contraindication, incapacitating pain, or claustrophobia) * Large tattoo present in the area of interest (artifacts) * Patients deprived of liberty, or under guardianship/curatorship * Patients receiving medical assistance (AME)