The leptomeningeal "ivy sign" on fluid-attenuated inversion recovery MR imaging in Moyamoya disease: a sign of decreased cerebral vascular reserve?
OBJECTIVE
Moyamoya disease is an idiopathic occlusive cerebrovascular disorder with abnormal microvascular proliferation. We investigated the clinical utility of leptomeningeal high signal intensity (ivy sign) sometimes seen on fluid-attenuated inversion recovery images in Moyamoya disease.


METHODS
We examined the relationship between the degree of the ivy sign and the severity of the ischemic symptoms in 96 hemispheres of 48 patients with Moyamoya disease. We classified each cerebral hemisphere into 4 regions from anterior to posterior. In 192 regions of 24 patients, we examined the relationship between the degree of the ivy sign and findings of single-photon emission CT, including the resting cerebral blood flow (CBF) and cerebral vascular reserve (CVR).


RESULTS
The degree of the ivy sign showed a significant positive relationship with the severity of the ischemic symptoms (P < .001). Of the 4 regions, the ivy sign was most frequently and prominently seen in the anterior part of the middle cerebral artery region. The degree of the ivy sign showed a negative relationship with the resting CBF (P < .0034) and a more prominent negative relationship with the CVR (P < .001).


CONCLUSIONS
The leptomeningeal ivy sign indicates decreased CVR in Moyamoya disease.
Mori
N
N
Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan. chihuahua@rad.med.tohoku.ac.jp
Mugikura
S
S
Higano
S
S
Kaneta
T
T
Fujimura
M
M
Umetsu
A
A
Murata
T
T
Takahashi
S
S
D000293:Adolescent; D000328:Adult; D002545:Brain Ischemia / Q000150:complications* / Q000473:pathology*; D002536:Cerebral Arteries / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008576:Meningeal Arteries / Q000473:pathology*; D008875:Middle Aged; D009072:Moyamoya Disease / Q000150:complications* / Q000473:pathology*; D012680:Sensitivity and Specificity; D055815:Young Adult