A 50-year-old woman with known Graves disease undergoes MRI of the orbits for evaluation of proptosis. Which of the following findings is most characteristic of thyroid eye disease?

• A Isolated enlargement of the superior ophthalmic vein
• B Diffuse enlargement of extraocular muscles including the tendinous insertions
• C Enlargement of extraocular muscles with sparing of the tendinous insertions ✓
• D Lacrimal gland enlargement with proptosis

Explanation

Thyroid eye disease (Graves orbitopathy) characteristically causes spindle-shaped enlargement of the extraocular muscle bellies with characteristic sparing of the tendinous insertions. The inferior rectus and medial rectus are most commonly involved. Enlargement including tendinous insertions is seen in orbital myositis. Superior ophthalmic vein enlargement suggests carotid-cavernous fistula or orbital venous congestion.

Reference: Radiology Review Manual, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.