2008-2009 / 2063
•
Suspension containing particles of
thorium dioxide
•
Contrast medium in X-ray diagnostics
in 1930s and 40s
•
Excellent images:
thorium has high absorption cross section
•
The naturally abundant nuclide
232
Th
is slightly unstable, decays through
emission of an alpha particle
•
Drug is distributed to
liver, spleen, lymph nodes, bone
•
Biological half-life is 22 years,
physical half life >10
10
years!