Pituitary gland MR: a comparative study of healthy volunteers and patients with microadenomas.

PURPOSE To compare the MR appearance of the pituitary glands of healthy volunteers with that of patients with microadenomas. METHODS Unenhanced coronal T1-weighted MR of the pituitary gland was performed on 52 healthy adult volunteers and 14 consecutive patients with evidence of pituitary adenomas. The MRs were interpreted in a randomized, blinded fashion. Notation was made of pituitary gland size, symmetry, stalk position, and the gland's signal uniformity. RESULTS Focal pituitary gland hypointensities were seen in 20 of 52 volunteers and in all 14 patients. In the volunteers, on average the areas of low signal were smaller and not as dark as in the patient group, but there was some overlap between the two groups. Pituitary gland size, symmetry, and stalk position did not differ between the two groups. CONCLUSIONS Focal hypointensities are common incidental MR findings in the healthy population. On average they appear smaller and not as dark as microadenomas.