Integrated PET/SPECT system for breast imaging with CdZnTe: Computational assessment

Breast specific gamma-ray imaging is gaining research attention as a mean to improve lesion detectability and patient management. Multimodality imaging is currently a hot topic of research with a gradually increasing number of systems installed in hospitals and new trends such as PET/MR and SPECT/MR. Cadmium Zinc Telluride (CdZnTe) pixelated detectors have the potential to lead in both these trends, allowing the design of flexible systems that can perform PET and SPECT imaging with the same detector material whereas being compact enough to be integrated with current MR systems. In the current study, the computational models of integrated PET/SPECT systems employing pixelated CdZnTe detectors in a stacked arrangement to achieve high detection efficiency were assessed in terms of spatial resolution. In addition to classic collimators for SPECT imaging, the possibility for electronic collimation is also investigated to greatly enhance the flexibility of the system. The models were constructed using a unique and realistic modeling framework that accurately handles charge transport effects in the detector and particle interactions in the system. Current preliminary results for PET imaging suggest that sub-centimeter resolution can be achieved.