Normative data for pituitary size and volume in the general population between 50 and 66 years

PURPOSE: The main aim of this study was to provide normative data for pituitary height and volume in persons between 50 and 66 years in the general population. The secondary aim was to establish a convenient surrogate marker of pituitary size for use in routine radiological practice. METHODS: From a geographically defined prospective healthy study, 1006 participants between 50 and 66 years had a brain MRI, of which 988 (519 women) were included in this study. We measured the mid-sagittal height, max-sagittal height and total volume of the anterior pituitary lobe based on T1-weighted 3D MRI images. RESULTS: Both the mean mid-sagittal and max-sagittal pituitary height were significantly larger in women compared to men, with 4.9 ± 1.7 mm versus 4.4 ± 1.4 mm (p < .001) for the mean mid-sagittal height and 6.8 ± 1.2 mm versus 6.1 ± 1.1 mm (p < 0.001) for the mean max-sagittal height. The mean anterior pituitary lobe volume was also significantly larger in women than in men (494 ± 138 mm(3) vs. 405 ± 118 mm(3)) (p < 0.001). There were no significant differences in these pituitary sagittal heights nor volume in either sex between the age groups 50–54, 55–59 and 60–66 years. The 95th percentile for mid-sagittal height, max-sagittal height and pituitary volume was 7.7 mm, 8.6 mm and 851 mm(3) for women and 6.6 mm, 7.8 mm and 610 mm(3) for men. CONCLUSION: This study show that women have a larger pituitary gland than men in the age group between 50 and 66 years and provides normative data for pituitary size estimates which can be used for clinical diagnostic purposes as well as future research.