[1] Hokkaido Univ, Sch Med, Dept Nucl Med, Kita Ku, Sapporo, Hokkaido 0608638, Japan
[2] Hokkaido Univ, Sch Med, Dept Gastroenterol, Kita Ku, Sapporo, Hokkaido 0608638, Japan
[3] Hokkaido Univ, Sch Med, Dept Hematol, Kita Ku, Sapporo, Hokkaido 0608638, Japan