findings in patients undergoing transsphenoidal surgery of pituitary macroadenomas in order to evaluate the ability of wanted to evaluate the usefulness of i.v. contrast medium in these patients. MR findings before and after transsphenoidal surgery were evalimages with 2 or 4 acquisitions were obtained, using 3-mm slice thickness and 0.3-mm interslice gaps. Of 18 M R examinations, 13 included coronal i.v. contrast medium enhanced images. Image uated in 6 cases. TI-weighted (T R / T E 600/20) sagittal and coronal MR to demonstrate the anatomic results. Furthermore, we quality, sinus cavernosus invasion, identification of normal pituitary tissue and tumor size were examined. All M R studies clearly demonstrated the macroadenomas whether 2 or 4 acquisitions were used, and whether i.v. contrast medium was administered or not. Surgically confirmed sinus cavernosus infiltration was seen in 4 patients. The pituitary stalk was identified separate from the tumor in 2 patients. and the gland in one. There was reduction in tumor size over time, indicating that final radiologic assessment after transsphenoidal surgery is best performed 4 to 6 months postoperatively. It should not be necessary t o routinely include i.v. contrast medium injection in the postoperative evaluation of macroadenomas.