“…Nevertheless, collateral vessels in MMA have a very complex angioarchitecture and are difficult to investigate, even with superselective DSA. Recently, Baltsavias et al [32][33][34] first and precisely demonstrated the collateral circulations in pediatric Moyamoya disease by superselective DSA with microcatheters. However, superselective DSA is accompanied by considerable risks for cerebral hemorrhage because of vessels that might be injured by the microcatheter, especially in fragile Moyamoya collaterals.…”