Évaluation de l'Impact du Compressed Sensing Sur le Signal QSM

Patients who have agreed to participate in the study will complete the MRI protocol as part of routine care, to which a maximum of four additional 25-minute sequences will be added.

MRI of routine care includes at least the following sequences:

• 3D T1 TFE (2 minutes)
• T2 TSE (2 minutes)
• 3D FLAIR (3 minutes)

The sequences added by the research lasting 25 minutes are:

• SWI QSM 1.0iso 8 echoes (10 minutes)
• SWI QSM 1.0iso 8 echoes CS 6 (7 minutes)
• SWI QSM 1.0iso 8 echoes CS 9 (5 minutes)
• SWI QSM 1.0iso 8 echoes CS 12 (3 minutes)

Inclusion criteria

For patients with MS:

• Patient over 18 years old
• Presenting MS defined according to McDonald's revised criteria for spatial and temporal clinical or radiological dissemination [16],
• Should benefit as part of the care of an MRI examination with or without injection of gadolinium
• Express consent to participate in the study
• Affiliate or beneficiary of a social security scheme

For patients with an indication to undergo a brain MRI and at low risk of inflammatory CNS disease:

• Patient over 18 years old
• Should benefit as part of the care of an MRI examination with or without injection of gadolinium
• Express consent to participate in the study
• Affiliate or beneficiary of a social security scheme

Exclusion criteria

• For patients with MS:
• Patient benefiting from a legal protection measure
• Pregnant or breastfeeding woman

For patients with an indication to undergo a brain MRI and at low risk of inflammatory CNS disease:

• Patient benefiting from a legal protection measure
• Pregnant or breastfeeding woman
• Patient with inflammatory and / or demyelinating pathology of the CNS

Secondary exclusion criteria :

• Motion artefact not allowing interpretation of images
• Patient who did not perform one of the following sequences: 3D T1 TFE, 3D FLAIR (for MS patients), SWI QSM 1.0iso 8 echoes.

Secondarily excluded patients will be replaced.