title: Pituitary adenomas: findings of postoperative MR imaging.
abstract: Preoperative and postoperative magnetic resonance (MR) images obtained in 25 patients with pituitary macroadenomas (1.1-5.2 cm in diameter) were evaluated to determine normal (physiologic) and abnormal findings after transsphenoidal or subfrontal surgery. With a 1.5-T unit, T1-weighted sagittal and coronal images were obtained before and after administration of gadopentetate dimeglumine. The physiologic changes after surgery included resorption of packing material and sphenoid sinus opacifications, reexpansion of the pituitary gland, and lowering of the optic chiasm. Implanted gelatin foam appeared as an endosellar, circularly enhancing mass that was seen on follow-up studies to have decreased in size. Muscle-and-fat implants appeared as areas of high signal intensity. In 14 patients, residual tumors were found in the suprasellar (n = 4), retrosellar (n = 3), parasellar (n = 8), and/or endosellar (n = 3) space. Residual tumors were differentiated from implant materials by means of location, characteristic signal intensity, and enhancing pattern, which were identical to those of the corresponding preoperative adenoma in 13 cases (93%). Preoperative studies and clinical information are helpful in the evaluation of postoperative MR imaging examinations.
authors.affiliation: Magnetic Resonance Institute, University of Vienna, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Steiner
authors.forename: E
authors.initials: E
authors.lastname: Knosp
authors.forename: C J
authors.initials: CJ
authors.lastname: Herold
authors.forename: J
authors.initials: J
authors.lastname: Kramer
authors.forename: R
authors.initials: R
authors.lastname: Stiglbauer
authors.forename: K
authors.initials: K
authors.lastname: Staniszewski
authors.forename: H
authors.initials: H
authors.lastname: Imhof
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005781:Gelatin Sponge, Absorbable / Q000737:chemistry / Q000627:therapeutic use; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009897:Optic Chiasm / Q000473:pathology; D010902:Pituitary Gland / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000473:pathology / Q000601:surgery*; D011182:Postoperative Care; D011300:Preoperative Care; D019736:Prostheses and Implants; D012189:Retrospective Studies; D012658:Sella Turcica / Q000473:pathology*; D013101:Sphenoid Sinus / Q000473:pathology