title: Spoiled gradient recalled acquisition in the steady state technique is superior to conventional postcontrast spin echo technique for magnetic resonance imaging detection of adrenocorticotropin-secreting pituitary tumors.
abstract: Recent studies show that the standard T1-weighted spin echo (SE) technique for magnetic resonance imaging (MRI) fails to identify 40% of corticotrope adenomas. We hypothesized that the superior soft tissue contrast and thinner sections obtained with spoiled gradient recalled acquisition in the steady state (SPGR) would improve tumor detection. We compared the performance of SE and SPGR MRI in 50 patients (age, 7-67 yr) with surgically confirmed corticotrope adenoma. Coronal SE and SPGR MR images were obtained before and after administration of gadolinium contrast, using a 1.5 T scanner. SE scans were obtained over 5.1 min (12-cm field of view; interleaved sections, 3 mm). SPGR scans were obtained over 3.45 min (12- or 18-cm field of view, contiguous 1- or 2-mm slices). The MRI interpretations of two radiologists were compared with findings at surgical resection. Compared with SE for detection of tumor, SPGR had superior sensitivity (80%; confidence interval, 68-91; vs. 49%; confidence interval, 34-63%), but a higher false positive rate (2% vs. 4%). We recommend the addition of SPGR to SE sequences using pituitary-specific technical parameters to improve the MRI detection of ACTH-secreting pituitary tumors.
authors.affiliation: Department of Radiology, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1583, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Patronas
authors.forename: Nail
authors.initials: N
authors.lastname: Bulakbasi
authors.forename: Constantine A
authors.initials: CA
authors.lastname: Stratakis
authors.forename: Antony
authors.initials: A
authors.lastname: Lafferty
authors.forename: Edward H
authors.initials: EH
authors.lastname: Oldfield
authors.forename: John
authors.initials: J
authors.lastname: Doppman
authors.forename: Lynnette K
authors.initials: LK
authors.lastname: Nieman
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000378:metabolism* / Q000601:surgery; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000328:Adult; D000368:Aged; D002648:Child; D005189:False Positive Reactions; D005682:Gadolinium / Q000008:administration & dosage; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000601:surgery; D012680:Sensitivity and Specificity
chemical_list: D000324:Adrenocorticotropic Hormone; D005682:Gadolinium