A patient developed proptosis and diplopia of 2 months duration following injury. On examination there is chemosis, conjunctival redness, and external ocular nerve palsy. Investigation of choice is:

Ans. (d) Intra-arterial digital subtraction angiographyRef: Kanski 7/e, p. 95, 96History of trauma with proptosis, chemosis and ophthalmoplegia indicates carticocavernous fistula* Investigations: CT and MR may demonstrate prominence of the superior ophthalmic vein and diffuse enlargement of extraocular muscles. The ultimate test, however, is selective arteriography of both internal and external carotid arteries.