THE USE OF CDTE OR CDZNTE FOR PULSE-COUNTING AND CURRENT-MODE MEDICALIMAGING APPLICATIONS

Recent progress in CdTe and CdZnTe detector research has made these de tectors appear attractive for medical imaging. As part of a feasibilit y study, Monte Carlo simulations have been developed to investigate th e detection efficiency and scatter rejection capabilities of these mat erials at diagnostic energies. We have also analyzed the count rate li mitations and current mode capabilities of Cd(Zn)Te. This preliminary work indicates that the 3-4 keV FWHM energy resolution and the 10(5) c ps/channel of which these detectors are capable should be adequate for most applications. In addition, although further experimental measure ments are needed, we expect that the current mode operation of these d etectors is acceptable for many systems. The major drawback of Cd(Zn)T e detectors is the low photopeak efficiency at 140 keV. In order to im prove this efficiency, we have examined both a novel singular-value-de composition (SVD) algorithm and a hardware-based technique to correct for spectral distortion arising from charge trapping.