title: Influence of age and sex on signal intensities of the posterior lobe of the pituitary gland on T1-weighted images from 3 T MRI.
abstract: OBJECTIVE
  To elucidate the influence of age and sex on the signal intensity (SI) of the posterior lobe of the pituitary gland (PPG) on T1-weighted images (T1WI) from 3 T MRI.
  
  
  METHODS
  Sagittal T1WI acquired from three-dimensional fast spoiled gradient recalled acquisition in the steady state in 1,634 subjects without conditions affecting antidiuretic hormone were evaluated retrospectively. The presence or absence of a bright signal in the PPG was assessed qualitatively. The SI ratio of the PPG to the pons (SIR) was obtained from quantitative measurements. We statistically analyzed these data, creating 14 subject groups categorized according to age and sex, and applied a Poisson generalized linear model to the SIR data.
  
  
  RESULTS
  The characteristic bright signal was absent in 47 subjects (2.8 %), with no significant difference in incidence among the groups. The SIR was inversely related to age in both males (r > 0.7) and females (r > 0.9), and was significantly higher in females in the third to the eighth decades (p < 0.05). Analysis of the whole SIR dataset using a generalized linear model showed that the estimated SIR decreased by 1.7 % per decade and is higher in females.
  
  
  CONCLUSIONS
  Age and sex influence the SI of the PPG on T1WI. These findings may aid the recognition of PPG signal abnormalities on T1WI.
authors.affiliation: Department of Radiology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashiku, Tokyo 173-8605, Japan. asakonemurinomori@yahoo.co.jp
authors.forename: Asako
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oba
authors.forename: Shigeru
authors.initials: S
authors.lastname: Furui
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D010904:Pituitary Gland, Posterior / Q000473:pathology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017678:Sex Distribution