Current approaches to hypothalamic-pituitary radiology.

Currently computed tomography (CT) is the primary imaging modality for pituitary and hypothalamic lesions, although it is probable that NMR will supersede it. The range of size of the normal pituitary is considerable, with relatively larger glands occurring in adolescence and females of childbearing age. Asymptomatic microadenomas and cysts are not infrequent so that small low-density lesions in a gland on the borderline of enlargement can only be assessed in relation to clinical presentation. Patients presenting with clinical or biochemical evidence of abnormal pituitary hormone secretion or with an enlarged sella but without evidence of any neurological abnormality are likely to have either a small pituitary tumour or an empty sella and are investigated by thin section high resolution CT to produce coronal and sagittal images. Visual defects, paralysis of ocular muscles or hypothalamic disturbances, in the absence of clinical evidence of hypersecretion of pituitary hormones, may be due to a variety of pathologies. These cases are elucidated by plain plus contrast-enhanced CT, supplemented as necessary by angiography and computed cysternography after injection of non-ionic contrast media. Hypothalamic disturbances may occasionally complicate cerebral malformations which are also elucidated by cranial CT.