Plain radiography of the pituitary region is essential, and lateral and anteroposterior (AP) views of the pituitary fossa should be taken.
The presence of a normal pituitary fossa does not preclude the presence of a pituitary tumour, since ninety per cent of patients with Cushing's disease, and twenty per cent of prolactinoma patients, also have normal fossae. With parasellar lesions causing hypopituitarism, the plain skull radiographs may be normal, and an abnormality may be revealed only using computerised tomography (CT) scanning or magnetic resonance imaging (MRI). CT scanning with facilities for reconstruction has revolutionised the assessment of patients with hypopituitarism. More recently, MRI has been introduced and may be more useful in the diagnosis of microadenomas (for example, Cushing's disease).