[1] Univ Ulsan, Coll Med, Dept Radiol, 88 Olymp Ro 43 Gil, Seoul 05505, South Korea
[2] Univ Ulsan, Coll Med, Asan Med Ctr, Res Inst Radiol, 88 Olymp Ro 43 Gil, Seoul 05505, South Korea
[3] Harvard Med Sch, Dana Farber Canc Inst, Dept Imaging, Boston, MA 02215 USA
[4] Harvard Med Sch, Brigham & Womens Hosp, Dept Radiol, Boston, MA 02115 USA