[1] Kwandong Univ, Coll Med, Myongji Hosp, Dept Radiol, Koyang City 412270, South Korea
[2] Kwandong Univ, Coll Med, Myongji Hosp, Dept Neurol, Koyang, South Korea
[3] Catholic Univ Korea, Dept Radiol, Seoul, South Korea
[4] Univ Toronto, Toronto Western Hosp, Dept Med Imaging, Toronto, ON, Canada