Imaging of the pituitary.

In the appropriate clinical setting of pituitary hyperfunction or hypofunction, visual field deficit, or cranial nerve palsy, imaging of the pituitary is necessary. This article reviews the normal appearance of the pituitary and its surroundings, emphasizing magnetic resonance imaging. Typical and variant appearances of pituitary pathology are discussed. Because growth of adenoma into surrounding structures is important to surgical management, cavernous sinus invasion and suprasellar spread as well as adenoma mimics are illustrated. Typical examples of pituitary dysfunction from other entities that secondarily affect the gland, hypophysis, or third ventricle are discussed. Some common errors of interpretation are listed.