*Case Summary: 8 mm nodular lesion in the clivus, hyperintense on T1 and T2.

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*What is a Clival Hemangioma?

 

•Benign vascular tumor arising within bone

 

 

•Usually incidental finding

 

•Often asymptomatic

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*Why Hyperintense on T1? 

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•High signal from vascular pools and fatty content

 

•T1 hyperintensity is a typical feature

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*Why Hyperintense on T2?

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•High water content and vascular channels → long T2 signal

 

•Bright, well-defined appearance on MRI

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*Clue: Typical trabecular (“polka-dot”) pattern on CT

 

💡 Why Polka-Dot Pattern on CT?

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Bone trabeculae preserved between vascular channels

 

Small round densities on axial CT

 

Key differential diagnostic feature

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*Clival Hemangioma – Differential Diagnosis

 

•Chordoma: Midline, destructive, very hyperintense on T2 with septations (“soap-bubble”).

 

•Chondrosarcoma: Off-midline, chondroid calcification (“rings & arcs” pattern).

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•Meningioma: Dural-based, homogeneous strong enhancement, often with “dural tail”.

 

•Metastasis: Variable, usually heterogeneous, marked bone destruction with soft-tissue mass.

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•Plasmacytoma: Solitary, lytic, sharply demarcated, homogeneous enhancement. 

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•Hemangioma: Hyperintense on T1/T2, honeycomb or polka-dot trabecular pattern, expansile but less aggressive.

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*Contrast was not used in this case. If administered, hemangioma usually shows early homogeneous enhancement, followed by contrast gradually filling the internal spaces. This creates:

 

•“Puzzle-piece” pattern: Different compartments of the lesion enhance at different times,

resembling puzzle pieces fitting together.

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•“Filling-in” pattern: Over time, contrast fills the lesion completely, becoming uniformly enhanced.