The dysthyroid orbitopathy (DO) is a chronic disease, evolving during 2 to 3 years, with a hypertrophy and a variable degree of inflammation of the eyelid muscles, the oculomotor muscles and the orbital fat.

If the diagnosis of OD is primarily clinical and laboratory, MRI is an additional contribution to the clinic, guiding the therapeutic management by detecting inflammatory lesions not found on clinical examination in 1/3 of cases.

The three MRI sequences conventionally practiced ((T2, T2-fat-sat, T1) allow muscles signal analysis oculomotor abnormalities as well as the orbital fat.

Compared to these sequences, the main advantage sequences DIXON is a faster acquisition. In addition, DIXON type of imaging overcomes most of these artifacts and to obtain a homogeneous fat removal.

Inclusion Criteria:

• Patient aged 18 to 90 years, suffering from thyroid dysfunction proved by clinical and laboratory tests, with a bilateral clinical dysthyroid orbitopathy and undergoing an eye MRI

Exclusion Criteria:

• Absolute or relative contra-indication to MRI or to a contrast agent gadolinium injection (including pregnant or likely to be, breastfeeding women)
• Patient under guardianship
• Patient not willing to participate.
• Lack of affiliation to social security or medical state aid (AME) or universal health coverage (CMU)
• Motion artifact on the sequences, not corrected by the repeat sequences
• Metal artifact prohibiting the analysis of the region of interest

Patients with a dysthyroid orbitopathy undergoing a MRI