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Topic

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Sella turcica

The sella turcica is a saddle-shaped depression in the body of the sphenoid bone, located in the middle cranial fossa at the skull base. It houses the pituitary gland (hypophysis) and is bounded anteriorly by the tuberculum sellae, posteriorly by the dorsum sellae, and laterally by the cavernous sinuses. The floor of the sella forms the roof of the sphenoid sinus, and the pituitary gland sits within the hypophyseal fossa, surrounded by dura mater and cerebrospinal fluid. The sella turcica varies in size and shape among individuals, with clinical relevance in pituitary tumors, endocrine disorders, and cranial imaging.

Synonyms

  • Pituitary fossa

  • Hypophyseal fossa

  • Sphenoid saddle

Function

  • Provides a bony enclosure and protection for the pituitary gland

  • Maintains the position of the pituitary within the skull base

  • Serves as a landmark in cranial and radiological anatomy

  • Allows passage of surrounding neurovascular structures such as the cavernous sinuses and internal carotid arteries

MRI Appearance
T1-weighted images:

  • The sella turcica appears as a bony hypointense boundary surrounding the pituitary gland, which is intermediate signal intensity relative to brain tissue

  • The cerebrospinal fluid in the subarachnoid space above the pituitary may appear hyperintense, creating natural contrast

  • Pituitary adenomas or lesions may appear hypo- or hyperintense, often enhancing after contrast

T2-weighted images:

  • The pituitary gland is intermediate to slightly hyperintense, while CSF in the suprasellar cistern is bright

  • Surrounding bony margins remain hypointense, delineating the sella

  • Useful for identifying cystic lesions, edema, or structural abnormalities

STIR (Short Tau Inversion Recovery):

  • Fat suppression highlights soft tissue pathology around the pituitary

  • Normal sella turcica and pituitary remain low to intermediate signal, while tumors, inflammation, or cysts appear hyperintense

CT Appearance

  • On CT, the sella turcica appears as a well-defined bony depression in the sphenoid body, with the pituitary gland itself not directly visualized unless calcified or enlarged

  • Cortical margins of the tuberculum sellae, dorsum sellae, and lateral walls are hyperdense

  • Surrounding air in the sphenoid sinus appears hypodense, providing natural contrast for evaluating floor defects or erosion

  • Useful for assessing bony erosion by tumors, congenital anomalies, or fractures

MRI images

Sella Turcica mri coronal image -img-00000-00000

X Ray image

Sella turcica