Which imaging modality is used to diagnose Moyamoya disease and visualize collateral networks?

• A. Cerebral angiography or MR angiography
• B. EEG
• C. CT
• D. X-ray skull

Answer: (A)

Moyamoya disease is diagnosed by directly visualizing the blood vessels in the brain to see both the narrowing of the main arteries and the abnormal collateral networks that develop to compensate for reduced flow. Cerebral angiography, using catheter-based digital subtraction angiography, provides a detailed map of the intracranial vessels and reveals the characteristic fine, tangled collateral vessels that look like smoke, hence the name “puff of smoke.” This makes it the gold standard for confirming the diagnosis and assessing the extent of disease.

MR angiography offers a noninvasive way to visualize the same vascular architecture and collaterals, making it a practical alternative when avoiding catheter-based procedures. Together, these vascular imaging approaches are specifically suited to identifying Moyamoya’s collateral networks.

Other options don’t fit the goal of visualizing blood vessels: EEG measures electrical brain activity, not vasculature; CT can show brain tissue changes but not the detailed collateral networks; X-ray of the skull doesn’t visualize intracranial vessels.