KEY FACTS Terminology Benign, often partially cystic sellar region tumor derived from Rathke pouch epithelium 2 types Adamantinomatous (cystic mass in childhood) Papillary (solid mass in older adults) Imaging General features Multilobulated, often large (> 5 cm) Occasionally giant, multicompartmental…
KEY FACTS Terminology Nonneoplastic cyst arising from remnants of embryonic Rathke cleft Benign sellar region endodermal cyst lined by ciliated, mucus-producing epithelium Imaging Nonenhancing, noncalcified, intrasellar &/or suprasellar cyst with intracystic nodule Completely intrasellar (40%), suprasellar extension (60%) Density/signal intensity…
KEY FACTS Terminology Acute clinical syndrome with headache, visual defects/ophthalmoplegia, altered mental status, variable endocrine deficiencies Caused by either hemorrhage or infarction of pituitary gland Preexisting pituitary macroadenoma common Imaging CT Sellar/suprasellar mass with patchy or confluent hyperdensity Peripheral enhancement,…
KEY FACTS Terminology Benign neoplasm of adenohypophysis Imaging Upward extension of macroadenoma = most common suprasellar mass in adults Best imaging technique MR with sagittal/coronal thin-section imaging through sella + T1 C+ with FS Sellar mass without separate identifiable pituitary…
KEY FACTS Terminology Microadenoma: ≤ 10 mm in diameter Imaging Intrasellar mass is typical location Rare: Ectopic origin outside pituitary fossa Best technique = dynamic contrast-enhanced thin-section T1-weighted MR Generally enhance more slowly than adjacent normal pituitary Beware: 10-30% can…
KEY FACTS Terminology Congenital anomalies of pituitary stalk → potential hypothalamic/pituitary axis malfunction Imaging Posterior pituitary ectopia (PPE) Duplicated pituitary gland/stalk (DP) PPE: No (or tiny) pituitary stalk, ectopic posterior pituitary on midline sagittal T1WI MR Look for associated anomalies:…
Gross Anatomy Sella Bony anatomy : The sella turcica (“Turkish saddle”) is a concave, midline depression in the basisphenoid that contains the pituitary gland (also called the hypophysis). The anterior borders of the sella are formed by the anterior clinoid…
KEY FACTS Terminology Hydrocephalus Enlargement of cerebral ventricles secondary to abnormal cerebrospinal fluid (CSF) formation, flow, or absorption resulting in ↑ CSF volume Imaging Shunt failure → dilated ventricles + edema around ventricles, along catheter and reservoir Use CT or…
KEY FACTS Terminology Normal pressure hydrocephalus (NPH) Ventriculomegaly with normal cerebrospinal fluid (CSF) pressure, altered CSF dynamics Imaging Enlarged lateral & 3rd ventricles, 4th ventricle relatively normal Disproportionately large ventricles compared with subarachnoid spaces (particularly sylvian fissures and basal cisterns)…
KEY FACTS Terminology Focal reduction of cerebral aqueduct diameter Imaging Ventriculomegaly of lateral and 3rd ventricles with normal-sized 4th ventricle ± periventricular interstitial edema (uncompensated hydrocephalus) Multiplanar MR with sagittal 3D-heavy T2WI sequences and sagittal cardiac-gated cine MR Top Differential…