Height of normal pituitary gland on MR imaging: age and sex differentiation.

Measurement of the pituitary height was performed on magnetic resonance (MR) images of 213 subjects with no known or suspected pituitary and/or hypothalamic disorders. Midsagittal, T1-weighted images were used for measurements and mean heights in each age and sex group were obtained. In the 10 to 69 year range, the pituitary heights were greater in females than in males. The groups of 0-9 years of both genders showed the minimum mean pituitary height. The maximum of the mean height was observed in the 10 to 19 year age groups of both genders. The height gradually decreased with increasing age after age 20 years. There were no subjects with a height of greater than or equal to 9.0 mm in females or greater than or equal to 8.0 mm in males. There was a marked discrepancy between MR and autopsy findings in the older subjects, probably related to the upward concavity that is often encountered in the aged gland. Because of this concavity, the midsagittal MR measurement will induce underestimation of the whole gland.