The results of our investigation on the performance of bismuth germanate crystals (Bi4Ge3O12 or BGO) employed in positron emission tomography are presented. BGO energy resolution to low energy gamma rays can be enhanced by working the lateral surfaces in a convenient mode. The BGO behaviour has been measured down to -70-degrees-C to establish the relevance of temperature-related drift to peak broadening. Variations of both light output and decay time have been investigated and compared with previous results. A series of tests is presented where the improvement in response of the BGO crystals, in terms of energy resolution, is evaluated using thermalized crystals. In order to improve the BGO performance in time of flight tomography, where building shorter coincidences. (i.e., reducing the overlap time between two independent signals) means not only decreasing the peak/noise ratio, but also reducing the dose absorbed by the patient, we have investigated the BGO energy resolution with the photomultiplier pulses clipped down to 100 ns.
Characterization And Performance Of Bgo Crystals For Positron Emission Tomography
GERVINO, Gianpiero;
1994-01-01
Abstract
The results of our investigation on the performance of bismuth germanate crystals (Bi4Ge3O12 or BGO) employed in positron emission tomography are presented. BGO energy resolution to low energy gamma rays can be enhanced by working the lateral surfaces in a convenient mode. The BGO behaviour has been measured down to -70-degrees-C to establish the relevance of temperature-related drift to peak broadening. Variations of both light output and decay time have been investigated and compared with previous results. A series of tests is presented where the improvement in response of the BGO crystals, in terms of energy resolution, is evaluated using thermalized crystals. In order to improve the BGO performance in time of flight tomography, where building shorter coincidences. (i.e., reducing the overlap time between two independent signals) means not only decreasing the peak/noise ratio, but also reducing the dose absorbed by the patient, we have investigated the BGO energy resolution with the photomultiplier pulses clipped down to 100 ns.
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