1. From the Department of Neurology, Samsung Medical Center, Sungkyunkwan University, Seoul, South Korea (O.Y.B.); Department of Radiology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada (M.G.); and Neurovascular Imaging Research Core and Department of Neurology, Comprehensive Stroke Center, Geffen School of Medicine, University of California, Los Angeles (D.S.L.).