Non-invasive imaging of radiocesium dynamics in a living animal using a positron-emitting Cs tracer

Suzui, Nobuo*; Shibata, Takuya  ; Yin, Y.-G.*; Funaki, Yoshihito*; Kurita, Keisuke  ; Hoshina, Hiroyuki*; Yamaguchi, Mitsutaka*; Fujimaki, Shu*; Seko, Noriaki*; Watabe, Hiroshi*; Kawachi, Naoki*

Visualizing the dynamics of cesium (Cs) is desirable to understand the impact of radiocesium when accidentally ingested or inhaled by humans. The positron-emitting nuclide Cs was produced using the I (, 4n) Cs reaction, which was induced by irradiation of sodium iodide with a He beam from a cyclotron. We excluded sodium ions by using a material that specifically adsorbs Cs as a purification column and successfully eluted Cs by flowing a solution of ammonium sulfate into the column. We injected the purified Cs tracer solution into living rats and the dynamics of Cs were visualized using positron emission tomography; the distributional images showed the same tendency as the results of previous studies using disruptive methods. Thus, this method is useful for the non-invasive investigation of radiocesium in a living animal.