Shingo Kato1, Kazuki Fukui2. 1. Departments of Diagnostic Radiology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawaku, Yokohama, Kanagawa, 236-0004, Japan. sk513@yokohama-cu.ac.jp. 2. Department of Cardiology, Kanagawa Cardiovascular and Respiratory Center, Yokohama, Japan.