IVY sign in major vessel stenosis

A  7yo patient came for MRI Brain with history ... no need to mention here as it was not specific and i am sure it was not related to patient's imaging findings. 

Only Axial FLAIR images of patient were abnormal with a subtle finding. Rest of the MRI study including Diffusion and GRE were absolutely normal.

Guess !! the finding.

Faint serpigenous high signal in right peri sylvian cortical sulci are the cortical branches of right MCA with sluggish flow attributed to IVY sign.

and that's his angio... 

Click image to enlarge. 

3 D TOF Non contrast MR Angiography of brain shows severe right MCA proximal main stem stenosis with sparsity of cortical branches of right MCA compared to left. 

'IVY' sign

Normally cortical branches of major intra cranial vessels which travel along hemispheric cortical sulci are not visualised on FLAIR.

Due to any reason if the flow in these cortical branches hampered, the slow flow in these cortical branches or the cortical collaterals developed thereby , reflect high signal on FLAIR, relatively higher than that of adjacent normal isointense brain parenchyma and seen as serpigenous hyperintensities in the region of cortical sulci on FLAIR attributed to IVY sign. 

IVY sign is reported in following conditions.

Moya Moya disease or major intra cranial vessel stenosis lead to cortical branches with slow flow or development of collaterals with sluggish flow.

Early ischemia thrombus in cortical branches may reflect high signal on FLAIR

Vasculopathies. 

To see similar cases with other causes of IVY sign : Click here

IVY sign Moyamoya disease MRI

A 21 yo male with history of transient ischemic attacks.
Here is his MRI Axial FLAIR and Non contrast 3 D TOF MR Angiogram of Brain

MRI Axial FLAIR images of brain show serpigenous T2 hyperintensities along the cortical sulci overlying bilateral cerebral convexities in perisylvain regions and along inter hemispheric fissure – ‘IVY’ sign. The proposed mechanisms for this high signals attributed to sluggish flow in cortical branches of ACA and MCA or retrograde slow flow in engorged pial vasculature due to leptomeningeal anastomosis.

MR Angiogram of brain shows steno occlusive lesions of anterior circulation of Circle of Willis; Intra cranial portions of ICAs, ACAs and MCAs are involved with marked sparsity of cortical branches on either side. 

No recent infarct on diffusion.

Imaging wise bilateral intra cranial steno occlusive lesions with ivy sign, possibility of arteriopathy and moyamoya disease suggested and advised DSA for further evaluation.

"IVY" sign is also reported in Vasculitis : Post Tb Meningitis Vasculitis induced infarcts with "IVY"sign