Presentation
Known Graves disease with prior radioactive thyroid treatment. Deteriorating vision.
Patient Data
Bilateral proptosis.
Bilateral symmetrical enlargement of the medial, inferior, superior and lateral rectus muscles. The enlargement is disproportionally involving the muscular bodies with sparing of the tendinous insertions. The medial and inferior rectus muscles are the most significantly enlarged.
Crowding of the optic nerve towards the orbital apex, but a thin rim (1mm) of perineural fat persists. On the STIR sequences, mild diffuse increased signal within the intraocular muscles is evident, suggestive of edema/inflammation.
Thickened right middle and inferior turbinates. No paranasal fluid.
Case Discussion
MR images to accompany a clinical history entirely consistent with thyroid associated orbitopathy.