What and why: the current situation and future prospects of “ivy sign” in moyamoya disease

Abstract

“Ivy sign” is a special imaging manifestation of moyamoya disease (MMD), which shows continuous linear or punctate high intensity along the cortical sulci and subarachnoid space on magnetic resonance images. Ivy sign was reported to reflect the development of compensatory collaterals, and to be closely related to hemodynamic changes and clinical symptoms, and to indicate the postoperative prognosis, in MMD patients. It is a unique and critical marker for MMD. However, due to the lack of consistent criteria, such as definition, grading, and identification standards, ivy sign has not received much attention. We undertook a comprehensive literature search and summarized the current situation regarding ivy sign in MMD in terms of baseline characteristics, detection methods, definition, regional division and distribution patterns, grading criterions, incidence, related factors, the mechanism of ivy sign, and the effects of treatments. We also provided related concerns raised and future prospects relevant to studies about ivy sign in MMD.

Advances in the Diagnosis and Treatment of Pediatric Arterial Ischemic Stroke

“…Some data suggest that radiographic progression and the presence of biomarkers such as the ivy sign may help stratify risk of clinical disease progression and identify patients likely to benefit from surgery [ 241 , 242 ]. The ivy sign is characterized by leptomeningeal fluid-attenuated inversion recovery (FLAIR) hyperintensity or contrast enhancement on T1-weighted images that looks like ivy growing along the sulci and subarachnoid space [ 243 ]. It represents engorgement of the pial vasculature and/or slow flow in leptomeningeal collateral vessels and is thought to indicate cerebral hypoperfusion and elevated stroke risk.…”