1 Department of Radiology, The Jikei University School of Medicine and University Hospital, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 1058461, Japan. akirababa@jikei.ac.jp.
2 Department of Otorhinolaryngology, The Jikei University School of Medicine and University Hospital, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 1058461, Japan.
3 Department of Radiology, The Jikei University School of Medicine and University Hospital, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 1058461, Japan.
4 Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
5 Department of Radiology, University of Michigan, 1500 E Medical Center Dr, UH B2, Ann Arbor, MI, 48109, USA.