[1] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Pulm & Crit Care Med, Seoul, South Korea
[2] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Radiol, Seoul, South Korea
[3] Univ Ulsan, Coll Med, Asan Med Ctr, Res Inst Radiol, Seoul, South Korea
[4] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Pulm & Crit Care Med,Ctr Pulm Hypertens & Ve, Olymp Ro 43 Gil, Seoul 05505, South Korea