[1] Natl Ctr Global Hlth & Med, Dept Radiol, Div Nucl Med, Shinjuku Ku, 1-21-1 Toyama, Tokyo 1628655, Japan
[2] Keio Univ, Sch Med, Div Nucl Med, Dept Radiol,Shinjuku Ku, 35 Shinanomachi, Tokyo 1608582, Japan
[3] Tokyo Metropolitan Geriatr Hosp, Dept Diagnost Radiol, Itabashi Ku, 35-2 Sakae Cho, Tokyo 1730015, Japan
[4] Inst Gerontol, Itabashi Ku, 35-2 Sakae Cho, Tokyo 1730015, Japan
[5] Univ Tokyo, Sch Med, Dept Geriatr Med, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138655, Japan