[1] Kyoto Univ, Grad Sch Med, Dept Resp Med, Sakyo Ku, Kyoto 6068507, Japan
[2] Kobe City Gen Hosp, Div Resp Med, Chuo Ku, Kobe, Hyogo 6500046, Japan
[3] Kobe City Gen Hosp, Div Thorac & Cardiovasc Surg, Chuo Ku, Kobe, Hyogo 6500046, Japan
[4] Kobe City Gen Hosp, Div Radiol, Chuo Ku, Kobe, Hyogo 6500046, Japan