Application of gadolinium in neutron capture therapy is under evaluation. Crucial to development of this therapy is an imaging technique that would show the distribution and concentration of parts-per-million amounts of I57Gd in sliced samples. A technique that utilizes the principles of autoradiography and neutron radiography has been tried. The images taken with this method display the gadolinium distribution and its relative concentration in samples. Concentrations of I57Gd ranging from ∼20 to 500 ppm can be determined. The intrinsic spatial resolution of the system used in the Missouri University Research Reactor is 70 μm.