<prompt> Kamla, age 48 yrs, presents with unilateral mild axial proptosis. There is no redness or pain. Investigation of choice is -T3 T4 measurement to rule out thyrotoxicosisCT scan to rule out meningiomaDoppler to rule out hemangiomaUSG to rule out orbital pseudotumor  <response>: Most common cause of proptosis in adult is thyroid ophthalmopathy and most cases are due to graves disease thyrotoxicosis. Therefore T3 T4 measurement should be done. 