of 99mTc was 140 keV with a 10% pulse height analyzer window.
was 364 keV with a [+ or -]10% window.
To measure the sample's activity, the photopeak
efficiency (FEPE) of the detector for each photon energy is needed.
Anterior cardiac images were acquired at 15 minutes and 4 hours postinjection on a 256 x 256 matrix and an acquisition time of 600 sec, using a 15% energy window centered at the 159 keV photopeak
Data come from the first escape (FE) peak in the case of the 100 cc detector and from the photopeak
in the case of the 300 cc detector.
For the TlBr crystal grown once, it was not possible to observe the photopeak
profile because the pulses generated fall in the electrical noise region.
Whole-body views were acquired on the 140 keV photopeak
with a 15% symmetrical window using a 256 x 1024 matrix.
Conclusion: The photopeak
efficiencies decrease as energy increases and the observed efficiency curves were closely with similar studies.
The samples are measured the next day for the induced Au-198 photopeak
at 411.8 KeV.
A window of 20% centered on the 140-keV photopeak
Daily spectra of radiation were measured throughout the whole experimental procedure, which made it possible to adjust the photopeak
windows during the measurements.
Silagadze, "A new algorithm for automatic photopeak
searches," Nuclear Instruments and Methods in Physics Research A, vol.