T1 Hyperintense Suprasellar Mass

Anne G. Osborn, MD, FACR

DIFFERENTIAL DIAGNOSIS

Common

Less Common

Rare but Important

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Most common cause for ↑ T1 is subacute hemorrhage
- T2* (GRE or SWI) useful
Age helpful in common diagnoses
- Children = craniopharyngioma
- Adults = pituitary macroadenoma, thrombosed aneurysm

Helpful Clues for Common Diagnoses

Pituitary Macroadenoma
- Hemorrhage, sometimes cystic change
Craniopharyngioma
- 90% Ca++, 90% cystic, 90% enhance
- “Crankcase” oily content → T1 hyperintensity

Helpful Clues for Less Common Diagnoses

Saccular Aneurysm (Thrombosed)
- Usually eccentrically located, not directly suprasellar
- Subacute/chronic mural thrombus
Rathke Cleft Cyst
- May have very short T1 if high protein content or hemorrhage from cyst apoplexy
- Look for intracystic nodule
- Look for “claw” of enhancing pituitary gland wrapped around cyst
Ectopic Neurohypophysis
- Pituitary stalk tiny or nonexistent
- “Bright spot” on hypothalamus
- Does not saturate with fat suppression
Lipoma
- Suppresses with fat saturation
Dermoid Cyst
- Fat droplets in sulci, cisterns (ruptured)

Helpful Clues for Rare Diagnoses

Pituitary Apoplexy
- Subacute hemorrhage has short T1
- Rim enhancement typical
Pilomyxoid Astrocytoma
- May hemorrhage
Cavernous Malformation
- “Popcorn” appearance
Meningioma
- ↓ T1 (psammomatous Ca++; hemorrhage, lipomatous transformation rare)