  The work shows the ability to visualize radiotracers used in SPECT with a
system based on a coded aperture mask and a hybrid pixel Timepix detector with
the CdTe sensor. Characterization of the system using X-rays and radioactive
sources confirms that the spatial resolution of less than 1 mm with a field of
view 3 cm x 3 cm can be achieved. The results of a simulation study to
determine the expected spatial resolution of the system in the focal plane for
the various radionuclides is presented. The possibility of using this system
with a thin (1.5 mm) coded aperture mask for reconstructing images of gamma
emitters with the energy up to 180 keV is demonstrated.
