Empty Sella (CT)	

Defects in the diaphragma sella may allow passage of cerebrospinal fluid (CSF) from the suprasellar cistern into the sella turcica, although it may also result from infarction or irradiation of a pituitary tumour. The condition is termed ‘empty sella’ and is usually an incidental finding. Differentiation from an intra- or suprasellar cyst is based on the normal location of the infundibulum, extending from the tuber cinereum to a small posteriorly displaced pituitary gland (Fig. 24.6). The clinical condition of ‘empty sella syndrome’ has been applied to the combination of an ‘empty sella’ with the constellation of symptoms: headache, endocrine dysfunction, and visual disturbances.

Fig. 24.6 Empty sella. Sagittal T1-weighted post-contrast MR image (a) showing a large ‘empty sella’, with an elongated infundibulum inserting into a thin enhancing pituitary gland. Coronal CT (b) in a different patient showing insertion of the infundibulum into a thin pituitary.