Walking away from stroke: simple step goals may stabilize artery plaque

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Patient with an carotid atheromatous plaque with ≥ 50% North American Symptomatic Carotid Endarterectomy Trial (NASCET) stenosis * Patient from vascular surgery department of the Louis Pradel Hospital of the Hospices Civils de Lyon, but not operated * Males and females aged over 18 years old * No contra-indication to physical activity with index performance (PS) \< 2 * Available and voluntary to invest in the study throughout its duration (6 months) * Able to understand, read and write French; * a social security system or similar; * Having dated and signed informed consent. Exclusion Criteria: * Transient ischemic attack (TIA) or ipsilateral cerebral infarction less than 6 months * History of ipsilateral carotid surgery or cervical irradiation; * Cancer, heart failure, seropositivity; * Coronary risk; * Renal failure (Cockcroft clearance of creatinine \< 30 milliliter/minute (mL/min); * Contraindication and precautions for use related to Prohance: hypersensitivity to the active substance or to any of the constituents of Prohance, renal insufficiency with clearance \<30 ml / min / 1.73 m², probability of convulsions during the higher examination in patients with epilepsy or brain injury, pregnancy, breastfeeding; * Contraindication to MRI: ferromagnetic material (including pacemaker, implantable defibrillators, cardiac valve prostheses, cochlear implants, neurostimulators, implanted automated injection equipment, intraocular metallic foreign bodies, neurosurgical and vascular clips); * Carotid occlusion; * ipsilateral intracranial stenosis; * Risk of pregnancy or proven pregnancy on interrogation data. Breastfeeding; * Patient under guardianship, under curatorship or safeguard of justice; * inability to express consent; * uncontrolled cardiological or neurological diseases; * Impossibility of being followed for medical, social, geographical or psychological reasons throughout the duration of the study.