title: MR Imaging of the Pituitary Gland and Postsphenoid Ossification in Fetal Specimens.
abstract: A thorough knowledge of fetal growth and development is key to understanding both the normal and abnormal fetal MR imaging findings. We investigated the size and signal intensity of the normal pituitary gland and the intrasphenoidal ossification around the Rathke pouch in formalin-fixed fetuses on MR imaging.
  
  
  
  Thirty-two fetuses with undamaged brains were included in this study (mean age, 19.93 weeks; age range, 12-31 weeks). Visual inspection of the pituitary and ossification around the Rathke pouch in the sphenoid bone or the postsphenoid ossification was conducted. The extent of pituitary and postsphenoid ossification, pituitary/pons signal ratio, and postsphenoidal ossification/sphenoid bone signal ratio was compared according to gestational age.
  
  
  
  The pituitary gland was identified as a hyperintense intrasellar structure in all cases, and postsphenoid ossification was identified as an intrasphenoidal hyperintense area in 27 of the 32 cases (84%). The mean pituitary/pons signal ratio was 1.13 ± 0.18 and correlated weakly with gestational age (R(2) = 0.243), while the mean postsphenoid ossification/sphenoid bone signal ratio was 2.14 ± 0.56 and did not show any increase with gestational age (R(2) = 0.05). No apparent change in the size of pituitary hyperintensity was seen with gestational age (R(2) = 0.001). Postsphenoid ossification showed an increase in size with gestational age (R(2) = 0.307).
  
  
  
  The fetal pituitary gland was hyperintense on T1-weighted images and the pituitary/pons ratio and extent of postsphenoid ossification correlated weakly with gestational age.
authors.affiliation: From the Department of Diagnostic Imaging and Nuclear Medicine (T.M.M., Y.F., Tomohisa Okada, M.K., A.Y., Tsutomu Okada, K.T.).
authors.forename: T M
authors.identifier: 0000-0003-2670-9993
authors.initials: TM
authors.lastname: Mehemed
authors.affiliation: From the Department of Diagnostic Imaging and Nuclear Medicine (T.M.M., Y.F., Tomohisa Okada, M.K., A.Y., Tsutomu Okada, K.T.) yfushimi@kuhp.kyoto-u.ac.jp.
authors.forename: Y
authors.identifier: 0000-0002-1982-3168
authors.initials: Y
authors.lastname: Fushimi
authors.affiliation: From the Department of Diagnostic Imaging and Nuclear Medicine (T.M.M., Y.F., Tomohisa Okada, M.K., A.Y., Tsutomu Okada, K.T.).
authors.forename: T
authors.identifier: 0000-0003-2312-5677
authors.initials: T
authors.lastname: Okada
authors.affiliation: From the Department of Diagnostic Imaging and Nuclear Medicine (T.M.M., Y.F., Tomohisa Okada, M.K., A.Y., Tsutomu Okada, K.T.).
authors.forename: M
authors.identifier: 0000-0002-9447-018X
authors.initials: M
authors.lastname: Kanagaki
authors.affiliation: From the Department of Diagnostic Imaging and Nuclear Medicine (T.M.M., Y.F., Tomohisa Okada, M.K., A.Y., Tsutomu Okada, K.T.).
authors.forename: A
authors.identifier: 0000-0002-8894-3622
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: From the Department of Diagnostic Imaging and Nuclear Medicine (T.M.M., Y.F., Tomohisa Okada, M.K., A.Y., Tsutomu Okada, K.T.).
authors.forename: T
authors.identifier: 0000-0001-8483-5096
authors.initials: T
authors.lastname: Okada
authors.affiliation: Human Health Science (T.T., S.Y.).
authors.forename: T
authors.identifier: 0000-0002-9660-9384
authors.initials: T
authors.lastname: Takakuwa
authors.affiliation: Human Health Science (T.T., S.Y.) Congenital Anomaly Research Center (S.Y.), Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: S
authors.identifier: 0000-0002-8194-6927
authors.initials: S
authors.lastname: Yamada
authors.affiliation: From the Department of Diagnostic Imaging and Nuclear Medicine (T.M.M., Y.F., Tomohisa Okada, M.K., A.Y., Tsutomu Okada, K.T.).
authors.forename: K
authors.identifier: 0000-0003-3615-1241
authors.initials: K
authors.lastname: Togashi
mesh_terms: D005333:Fetus / Q000000981:diagnostic imaging; D005865:Gestational Age; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D010012:Osteogenesis; D010902:Pituitary Gland / Q000000981:diagnostic imaging / Q000196:embryology*; D013100:Sphenoid Bone / Q000196:embryology