Department of Radiology, Boston Medical Center, Boston University School of Medicine, One Boston Medical Center Place, Boston, MA 02118, USA; Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, kita 15, nishi 7, kita-ku, Sapporo, Hokkaido 060-8638, Japan. Department of Radiology, Boston Medical Center, Boston University School of Medicine, One Boston Medical Center Place, Boston, MA 02118, USA. Department of Radiology, Michigan Medicine, 1500 East Medical Center Drive B2-A209A, Ann Arbor, MI 48109, USA. Department of Radiology, Boston Medical Center, Boston University School of Medicine, One Boston Medical Center Place, Boston, MA 02118, USA; Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, One Boston Medical Center Place, Boston, MA 02118, USA; Department of Otolaryngology-Head and Neck Surgery, Boston Medical Center, Boston University School of Medicine, One Boston Medical Center Place, Boston, MA 02118, USA. Electronic address: osamu.sakai@bmc.org.