Fig. 1

Measured energy spectra for Tc-99m and I-123 and for simultaneous dual-radionuclide scan: measured energy spectra for Tc-99m, I-123, simultaneous Tc-99m and I-123 dual-radionuclide scanning (dual), and sum of Tc-99m and I-123 spectra measured separately (I + Tc). Energy resolution of CdTe solid-state detector was good enough to distinguish photopeaks of Tc-99m (141 keV) and I-123. Settings for five energy windows are labelled. No differences in shapes between “dual” and “I + Tc” were observed