Ivy sign (brain)
Neuroimaging
assessment in Down syndrome: a pictorial review. Axial FLAIR image in a 12-year-old girl with Down syndrome and moyamoya pattern depicting the classical ivy sign, corresponding to areas of absence of normal FLAIR suppression of CSF within cortical sulci. This sign probably represents slow flow in leptomeningeal collaterals. The exam was performed without general anesthesia
The ivy sign refers to the MRI appearance of patients with moyamoya disease or moyamoya syndrome. Prominent leptomeningeal collaterals result in vivid contrast enhancement and high signal on FLAIR due to slow flow. The appearance is reminiscent of the brain having been covered with ivy.
Differential diagnosis
- leptomeningeal metastases
- subarachnoid hemorrhage
- meningitis
- high oxygen tension or hyperbaric O2 (100% O2)
