Topics

Topic

design image
Pituitary gland

The pituitary gland, also known as the hypophysis, is a small, pea-sized endocrine organ located at the base of the brain within the sella turcica of the sphenoid bone. Often called the “master gland,” it plays a pivotal role in regulating various hormonal functions throughout the body by secreting multiple hormones that influence other endocrine glands. The pituitary gland is closely related anatomically to the optic chiasm and cavernous sinuses, making its structural and vascular anatomy clinically significant, especially in radiology.

Synonyms

  • Hypophysis

  • Master gland

  • Hypophysis cerebri

  • Glandula pituitaria

Function

  • Regulates secretion of hormones affecting growth, metabolism, reproduction, and stress responses.

  • Divided into two main parts: anterior pituitary (adenohypophysis) and posterior pituitary (neurohypophysis).

  • Controls the thyroid gland (TSH), adrenal gland (ACTH), gonads (LH, FSH), lactation (prolactin), growth (GH), and water balance (ADH via posterior lobe).

  • Mediates feedback from peripheral endocrine glands.

Arterial Supply

  • Superior hypophyseal arteries (branches of the internal carotid artery): Supply the anterior pituitary and median eminence.

  • Inferior hypophyseal arteries (branches of the internal carotid artery): Supply the posterior pituitary.

  • Trabecular arteries: Minor contribution, especially to the infundibulum.

Venous Drainage

  • Primarily via the hypophyseal portal veins (drain anterior pituitary to cavernous sinus).

  • Posterior pituitary drains into the inferior hypophyseal veins.

  • All pituitary veins eventually drain into the cavernous sinus and then into the superior and inferior petrosal sinuses.

MRI Appearance

  • T1-weighted Imaging:

    • Normal pituitary gland is isointense to brain parenchyma.

    • Posterior pituitary bright spot: hyperintense due to neurosecretory granules (ADH).

    • Borders are well defined, stalk visible.

  • T2-weighted Imaging:

    • Pituitary gland is isointense to mildly hyperintense compared to brain tissue.

    • Posterior pituitary bright spot may appear less prominent or iso-hyperintense.

  • FLAIR Imaging:

    • Gland appears isointense, typically without significant contrast.

    • Posterior bright spot usually not prominent.

  • Post-Contrast T1-weighted Imaging:

    • Homogeneous, intense enhancement of both anterior and posterior lobes.

    • Pituitary stalk and diaphragma sellae may enhance.

    • Dynamic contrast imaging helps differentiate microadenomas (seen as hypointense lesions relative to enhanced gland).

CT Appearance

  • Appears as a soft tissue density within the sella turcica.

  • May be difficult to distinguish from adjacent bone without contrast.

  • Post-contrast: Gland enhances vividly due to its vascularity.

  • Pituitary stalk and posterior bright spot are usually not visible on CT.

  • Calcifications are rare but may be seen in certain tumors (e.g., craniopharyngioma).

MRI images

pituitary gland mri 3t axial image

MRI images

pituitary gland mri 3t coronal image

MRI images

pituitary gland mri 3t sagittal image

CT images

Pituitary gland CT sag image