Bright lesions on sellar/parasellar T1-weighted scans.

Eighty-seven patients with sellar and parasellar pathology were evaluated by magnetic resonance imaging to categorize lesions with hyperintensity on T1-weighted images. Postoperative fat packing after transsphenoidal hypophysectomy, intratumoral subacute or chronic hemorrhage in pituitary adenomas, and hemorrhagic or fat-containing craniopharyngiomas accounted for 33 of 35 abnormalities with short T1 values. Forty-three percent of nonsurgically treated pituitary adenomas had subacute intratumoral hemorrhage present. Using T2-weighted images to distinguish fat from subacute hemorrhage and attempting to identify the normal anterior pituitary gland on T1-weighted images may help to differentiate these three entities. T1-weighted images alone were not sufficient to distinguish between all sellar and parasellar masses.