Exploration of the pituitary stalk and gland by high-resolution computed tomography. Comparative study of normal subjects and cases with microadenoma.

By means of high-resolution CT, pituitary stalks and glands were demonstrated in 189 normal subjects and in six patients with microadenomas. In the horizontal view and in reconstructed coronal and sagittal projections, the normal stalks and glands showed homogeneous enhancement with the contrast medium. On metrizamide CT, the stalks and glands were demonstrated in high-density areas as a "defect". The detection-rate of the stalks and glands was more than 93.6% in all dimensions on enhanced CT and 100% on metrizamide CT. On reconstructed sagittal projections, there was a tendency for the glands to decrease in size with advancing age. Under the age of 29, especially in females, most of the glands were demonstrated as an oval area that filled the sella turcica. After the age of 50, the gland frequently was flattened with enlargement of the CSF space within the sella turcica, giving an appearance reminiscent of the "empty sella". Of six patients with microadenomas, five presented the appearance of oval gland, and one showed visualization of CSF space in the anterosuperior portion of the sella turcica. On reconstructed coronal projections, the angle of inclination of stalks was 1.5 +/- 1.2 degrees in normal subjects and 9.3 +/- 2.4 degrees in patients with microadenomas.