Evaluation of CZT Drift Strip Detectors for use in 3D Molecular Breast Imaging

X-ray mammography is a widely used technique for breast cancer screening. However, the technique is imprecise when it comes to radiographically dense breast tissue, and therefore a supplemental screening technique, such as Molecular Breast Imaging (MBI), could increase the cancer detection rate. Emerging technologies within MBI require excellent detector performance, preferably with a sub-millimetre intrinsic spatial resolution. A collaboration between Kromek and DTU Space aims to advance the DTU Space developed 3D CdZnTe (CZT) drift strip technology, for application in new emerging MBI systems. This collaboration has resulted in 10 compact 3D MBI test modules with the goal of producing high-performance and high yield detectors. In this article, we present overall excellent detector performance, sub-millimetre position resolution at both 122 keV and 661.6 keV, and good energy resolution for the applied electrode deposition and contact optimisation. Although the current experimental setup and results suffers from high electronic noise (using discrete NIM standard charge sensitive pre-amplifiers), we conclude that the measured spatial and spectral performance fulfill the expected requirements for the modules, with room for improvement, especially within limiting electronic noise. The detector test modules indicate a promising future for the 3D CZT drift strip technology within future emerging MBI systems.