Special characteristics and potential for dynamic function studies with PET.

The possibility of utilizing the PET approach to the investigation of dynamic physiologic processes has not been limited so far by radiation exposure to the patient but rather considerations by the technical limitations of PET imaging devices. In the past few years, several PET designs have been optimized specifically for fast dynamic studies. The most recent of these designs incorporates cesium fluoride detectors to achieve high counting rate capabilities. At this time, the value of fast dynamic studies with PET can be only theorized but expectations for the modality rest on solid physiologic hypotheses. The incorporation of time-of-flight information into the PET reconstruction process promises to further enhance the capabilities of fast PET devices by the improvement of temporal resolution through signal-to-noise ratio increase. PET devices incorporating time-of-flight information are beyond the drawing board stage and are now under construction.