In vivo assessment of pituitary gland volume with magnetic resonance imaging: The effect of age

We used sagittal and coronal Tl weighted magnetic resonance images, at 1.5 Tesla, to measure the height, width, length, and cross-sectional area and to generate two estimates of pituitary gland volume in 35 normal volunteers aged 26–79 yr (19 females and 16 males). Subjects over 50 yr of age had significantly smaller pituitary gland height (P = 0.03), area (P = 0.04), and volume (P = 0.04) than those under 50 yr (by two-tailed t test). Overall, age was negatively correlated with pituitary volume (V₁: r = −0.51; P = 0.003; V₂: r = −0.47; P = 0.008), area (r = −0.43; P = 0.009), and height (r = −0.46; P = 0.005), but not with pituitary length or width. There were no statistically significant differences in pituitary size between men and women (by two-tailed t test). These findings suggest that pituitary gland height provides a good single measure for the assessment of pituitary gland size and that age must be controlled for in studies of pituitary gland size.