Monolithic scintillator blocks in PET and SPECT

The monolithic scintillator block, read out by an APD array, is a very promising detector concept for PET. Some recent results demonstrating this are presented. Furthermore, using experimental information, we performed a simulation study of the position resolution of the monolithic blocks as a function of gamma-ray energy. The best resolution is obtained in the 140 –250 keV region, i.e. for
^99m
Tc and
¹¹¹
In, while at 364 keV (
¹³¹
I) the resolution is still good. Consequently the monolithic block approach can also be applied for SPECT. We discuss a combined PET/SPECT system employing monolithic scintillator block detectors.