Bony depression in sphenoid bone; contains pituitary gland. Seen as a central hypodense area bordered by bone.
Pituitary gland
Soft tissue density within the sella, best seen on contrast CT. Normal height: ~6–8 mm.
Pituitary stalk (infundibulum)
Thin structure extending from hypothalamus to pituitary. Better appreciated on MRI.
Optic chiasm
Located just above the sella; not well visualized on CT unless compressed.
Suprasellar cistern
CSF-filled space above sella, visualized as hypodensity.
Sphenoid sinus
Located anterior and inferior to sella. Helps in trans-sphenoidal approach.
Cavernous sinuses
Lateral to sella; contains ICA and cranial nerves III, IV, V1, V2, VI.
CT Imaging Appearance:
Non-contrast CT (NCCT):
Bony anatomy well visualized.
Useful for detecting calcification, hemorrhage, and bone erosion.
Contrast-enhanced CT (CECT):
Improves visualization of soft tissue lesions.
Pituitary gland and lesions enhance vividly.
Common Lesions of Sellar/Suprasellar Region:
🔴 1. Pituitary Adenoma (most common)
Microadenoma (<10 mm): Often iso- to hypodense on CT; faint or delayed enhancement.
Macroadenoma (>10 mm): Enlarges the sella, may erode floor or extend suprasellarly.
CT signs:
Sellar expansion.
Heterogeneous enhancement.
Suprasellar extension ± optic chiasm compression.
May show hemorrhage in apoplexy.
🟠 2. Craniopharyngioma
Bimodal age distribution (children & older adults).
CT findings:
Mixed cystic-solid mass in suprasellar region.
Calcification seen in 80–90%.
Enhancing solid components.
May cause hydrocephalus due to third ventricle compression.
🟡 3. Rathke’s Cleft Cyst
Non-enhancing cystic lesion in midline within sella/suprasellar.
CT: Well-defined, hypodense lesion without calcification or enhancement.
🔵 4. Meningioma (tuberculum sellae or diaphragma sellae)
Hyperdense mass with strong homogeneous enhancement.
May show calcification and adjacent bone hyperostosis.
Displaces optic chiasm and may mimic pituitary macroadenoma.
🟢 5. Aneurysm (especially ICA or ACoA)
Appears as a well-defined, round, hyperdense structure.
Enhances vividly with contrast.
Important to differentiate from tumors before surgery.
🟣 6. Hypothalamic/Hamartomatous lesions
Congenital or associated with syndromes.
Iso- to hyperdense mass in suprasellar region.
May cause precocious puberty or gelastic seizures.
⚪ 7. Metastasis / Lymphoma / Inflammatory Lesions
Can involve pituitary stalk or gland.
Appear as enhancing lesions.
Consider in systemic disease or diabetes insipidus.
CT Signs of Pathology:
Sign
Interpretation
Double floor sign
Floor erosion in pituitary macroadenoma.
Snowman or figure-of-8 sign
Suprasellar extension of pituitary macroadenoma.
Calcification
Suggests craniopharyngioma > meningioma.
Hyperostosis
Suggestive of meningioma.
Sellar enlargement
Seen in macroadenomas and large cysts.
Limitations of CT:
MRI is superior for soft tissue contrast, pituitary stalk visualization, and optic pathway assessment.
CT is still preferred for bone erosion, calcification, and emergency settings (e.g., apoplexy).
Conclusion:
CT imaging plays a vital role in assessing the bony architecture, calcifications, and emergency lesions of the sellar/suprasellar region. For soft tissue details and hormonal lesion evaluation, MRI remains the modality of choice, but CT continues to be an essential first-line tool in acute and structural assessments.
