1 Departments of Radiological Sciences, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan.
2 Departments of Radiological Sciences, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. Electronic address: ishimaru@nagasaki-u.ac.jp.
3 Department of Radiology, Nagasaki Goto Chuoh Hospital, Goto, Japan.
4 Department of Radiology, Nagasaki University Hospital, Nagasaki, Japan.