There are three different uses for Kromek CZT, represented by three medical imaging applications. They represent a trade-off in performance between energy resolution (% FWHM) and gamma photon flux.
- For SPECT gamma cameras and surgical probes, the energy resolution can be very good (< 4.0% at 140 keV) because the photon flux is less than 1,000 photons per second per square mm detector area.
- A medium flux x-ray photon application is represented by bone mineral densitometry, where fluxes reach a few million photons per second per square mm area).
- The highest fluxes are represented by photon-counting spectral CT where fluxes reach hundreds of millions of x-ray photons per second per square mm detector area. The energy resolution for this colour CT application is approx 15-20% in the clinical range of 80-140 keV peak.
Photon-counting spectral CT is under development at our partner OEMs.
We have achieved fluxes > 100 million pps/mm2 without polarization of the CZT detector arrays. We are currently working to speed up the readout electronics to avoid pulse pileup and to compensate for inter-pixel charge sharing, including k-escape fluorescence.