What Is Bright on T1W?

Situations where the pituitary gland demonstrates totally or partially a T1W hypersignal are well known: hemorrhage, fat, proteins, and melanine. Some situations are less known: with deposition of paramagnetic substances such as manganese in patients on long-term parenteral nutrition, in chronic liver diseases or in pregnant or lactating women. The pituitary gland may also demonstrate a T1W hyperintensity with venous flow impairment, for instance in patients with cavernous sinus arteriovenous fistula or giant aneurysm of the intracavernous internal carotid artery.