[1] Shanghai Jiao Tong Univ, Xinhua Hosp, Sch Med, Dept Neurol Surg, Shanghai 200030, Peoples R China
[2] Univ Pittsburgh, Dept Neurol Surg, Pittsburgh, PA 15260 USA
[3] Univ Washington, Med Ctr, Dept Anesthesiol, Seattle, WA 98195 USA
[4] Univ Pittsburgh, Dept Radiol, Pittsburgh, PA 15260 USA