Abstract
OBJECTIVE: The leptomeningeal ivy sign is a distinctive finding of Moyamoya disease (MMD), characterized by a linear high signal intensity along the cortical sulci on contrast-enhanced T1 magnetic resonance imaging (MRI) and fluid-attenuated inversion-recovery (FLAIR) MRI. We recently identified a similar linear enhancement along the cortical sulci using gadolinium-enhanced vessel wall MRI (VWMR) in patients with MMD. The aim of this study was to introduce the concept of the "VWMR ivy sign (VIS)". METHODS: Eighteen MMD patients underwent gadolinium-enhanced VWMR. We identified the VIS in gadolinium-enhanced VWMR, represented by a linear high intensity along the cortical sulci. The VIS was assessed by comparing pre and postcontrast T1 black blood sequences on VWMR and was investigated in the precentral, central, and postcentral sulci. "VIS scores" were calculated by the sum of VIS in the three sulci, ranged from 0 to 3. We compared the VIS scores according to different stroke presentations (non-stroke, ischemic stroke, and hemorrhagic stroke). The inter-modality agreement for identifying VIS and FLAIR/cortical sulci on contrast-enhanced T1 MRI (CEMR) ivy sign was determined using Cohen's kappa statistics. RESULTS: The VIS scores were significantly different among the three groups (p=0.004). The VIS scores in both the ischemic and hemorrhagic groups were significantly higher than those in the non-stroke group (ischemic vs. non-stroke, p=0.009; hemorrhagic vs. non-stroke, p=0.004). After adjusting for age and sex using the non-stroke group as a reference group, the VIS scores were significantly higher in the ischemic and hemorrhagic groups (p=0.046; odds ratio [OR], 8.27; 95% confidence interval [CI], 1.03-66.19 and p=0.039; OR, 7.78; 95% CI, 1.11-54.48, respectively). The intermodality agreement between VIS and FLAIR ivy sign was substantial in the precentral region, perfect in the central region, and substantial in the postcentral region (precentral sulcus : κ=0.609; 95% CI, 0.213-1; central sulcus : κ=1; and postcentral sulcus : κ=0.769; 95% CI, 0.475-1). Inter-modality agreement between the VIS and CEMR ivy sign was substantial in the precentral, central, and postcentral sulci, respectively (precentral sulcus : κ=0.727; 95% CI, 0.384-1; central sulcus : κ=0.609; 95% CI, 0.384-1; and postcentral sulcus : κ=0.649, 95% CI, 0.310-0.998). CONCLUSION: This preliminary series introduces the concept of VIS, possibly indicating slow and retrograde flow of sulcal vessels via leptomeningeal collaterals. Future studies are needed to develop an optimal scoring system for VIS and establish its clinical correlation with stroke presentations in MMD patients.