Magnetisation transfer imaging of the normal adenohypophysis: the effect of sex and age

Magnetisation transfer (MT) techniques provide tissue contrast depending ma inly on the concentration of macromolecules. Because many macromolecules ar e involved in the secretory activity of the pituitary gland, MT techniques might be useful in the study of pituitary gland disorders. Our purpose was to establish a quantitative database of the MT ratio (MTR) of the normal ad enohypophysis and to see whether there are age- and sex-related differences . Using a three-dimensional gradient-echo sequence for MT we studied the ad enohypophysis in 56 males and 61 females aged 7 months-77 years; postsatura tion images were obtained using an on-resonance binomial prepulse. The imag es were normal in all but three patients, two with meningiomas, one with a schwannoma). Adenohypophyseal MTR increased in both sexes up to 19 years of age (r = 0.47 males, 0.39 females, P < 0.05). In men after 20 years and in women from 20-49 years MTR decreased (r = -0.68, P < 0.001, r = -0.46, P < 0.05, respectively). In women aged 50-59 years the MTR again increased sli ghtly. The MTR in males was slightly higher at all ages except before 9 and after 50 years of age. These differences were not statistically significan t except in the 40-49 year group (P < 0.05).