Inclusion of Physiologic Data into Computerized Nuclear Medicine Dynamic Studies

A general technique has been developed for the multiplexing of time-dependent analog signals into the individual frames of a scintillation camera dynamic function study. A pulse train, frequency-modulated by the physiologic signal, is injected into a test input of a preamplifier servicing an outer phototube of the camera head. These tail pulses mimic photoevents occurring at a point outside of the camera's field of view, chosen to occupy a data cell in an unused corner of a computer-stored image. By selecting a region of interest encompassing this pulser peak, the resulting time-activity curve displays the desired physiologic variable in temporal synchronism with the radiotracer distribution.