A physical comparison of two fixed-angle emission tomographic cardiac imaging systems.

Two 7-pinhole tomographic imaging systems for large and small field-of-view gamma cameras were compared with a standard rotating slant-hole system in terms of planar resolution and resolution with depth. Other measurements include the determination of the depths of the reconstructed planes, image miniaturization and scintislice area variation with depth, the effect of scatter on resolution and the variation in resolution across the reconstructed plane. The pinhole sensitivities and the relative reconstructed sensitivities with depth were also measured. The rotating slant-hole system is found to have better depth resolution, a better scatter correction, has more uniform reconstructed sensitivities, is easier to position over the patient but requires significantly longer data acquisition times than the 7-pinhole system.