Imaging of Gamma Emission Near and Above the Operational Limit of a SPECT Scanner
C Pelletier*, J Jung, East Carolina Univ, Greenville, NCSU-E-I-82 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Purpose: To investigate the imaging of gamma emissions near the operational limit of a clinical SPECT scanner and determine whether higher energy gamma imaging is possible using a clinical scanner with no modifications.
Methods::A Philips BrightView SPECT scanner is used for this investigation. The system acquisition software imposes a maximum energy level of 960 keV. In order to investigate system response near this limit both simulations and clinical scans are performed. Gate 6.1 is used to simulate the system response to Europium-152 (Eu-152), a readily available gamma source with several high-energy gamma emissions. Simulations are validated using clinical scans of a Eu-152 source with a 700 keV to 960 keV window. In this energy range two major gamma emissions, 779 keV and 867 keV, are present. In addition, simulations of a high-energy (1.575 MeV) gamma emitter, Prasodymium-142 (Pr-142) are performed to determine if the NaI crystal is sufficient to image gamma emissions at this energy.
Results:Clinical measurements of Eu-152 show a FWHM of 14.0mm in this energy range. Simulated spectra of Eu-152 matches the measured spectra well, with a FWHM of 16.1mm. In addition, simulation of Pr-142 shows a clear photopeak in the detected spectrum at 1.575 MeV. This indicates the NaI crystal is sufficient for full absorption at this energy level.
Conclusion:This work indicates that the BrightView SPECT scanner has the potential to image high energy gamma. Simulations and clinical scans show the system is sufficient up to the maximum allowed acquisition energy. Simulation of Pr-142 shows the scanner is capable of imaging gamma up above 1.575 MeV, though acquisition software does not currently allow clinical validation. Additional research needs to be done to determine if there is the potential to overcome the software imposed maximum energy level, and if so, validation of the imaging of Pr-142 will be performed.