The Possible Difference of Underlying Pathophysiologies between 'Ivy Sign' on Contrast-Enhanced MRI and FLAIR

We read with interest the article by Wang et al[1][1] titled “Ivy Sign in Moyamoya Disease: A Comparative Study of the FLAIR Vascular Hyperintensity Sign Against Contrast-Enhanced MR Imaging.” The results of the study carried out by Wang et al are agreeable, which show that the ivy sign score on