title: Magnetic resonance imaging assessment of pituitary posterior lobe displacement in dogs with pituitary-dependent hyperadrenocorticism.
abstract: The displacement and signal intensity (SI) of the pituitary posterior lobe were evaluated on T1 weighted magnetic resonance (MR) images in 28 dogs with pituitary dependent hyperadrenocorticism (PDH). Compared with normal dogs, the posterior lobe was displaced dorsally in the pituitary of the PDH dogs. Correlation between the pituitary height/brain area (P/B) ratio and the displacement of the posterior lobe in the PDH dogs suggests that dorsal displacement of the posterior lobe increases in accordance with enlargement of the pituitary. As to the SI of the posterior lobe, the PDH dogs showed significantly lower SI in comparison to the normal dogs. Taken together, these results suggest that assessment of the displacement and SI of the posterior lobe of the pituitary on T1-weighted MR images is useful for the diagnosis of pituitary adenoma. In pituitary microadenoma that presents no apparent tumorigenesis on MRI, evaluation of these values may be useful for diagnosis and selection of an appropriate therapy.
authors.affiliation: Department of Small Animal Surgery 2, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034–8628, Japan. taoda@vmas.kitasato-u.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Taoda
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hara
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Masuda
authors.forename: Takahiro
authors.initials: T
authors.lastname: Teshima
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nezu
authors.forename: Akira
authors.initials: A
authors.lastname: Teramoto
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Orima
authors.forename: Shozo
authors.initials: S
authors.lastname: Okano
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tagawa
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D000308:Adrenocortical Hyperfunction / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology*; D004285:Dogs; D005260:Female; D008279:Magnetic Resonance Imaging / Q000662:veterinary*; D008297:Male; D010904:Pituitary Gland, Posterior / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D018709:Statistics, Nonparametric