Evaluation of CZT Drift Strip Detectors for Use in 3-D 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 submillimeter intrinsic spatial resolution. A collaboration between Kromek and DTU Space aims to advance the DTU Space developed 3-D CdZnTe (CZT) drift strip technology, for application in new emerging MBI systems. This collaboration has resulted in ten compact 3-D MBI test modules with the goal of producing high-performance and high yield detectors. In this article, we present overall excellent detector performance, submillimeter position resolution at both 122 and 661.6 keV, and good energy resolution for the applied electrode deposition and contact optimization. Although the current experimental setup and results suffer from high electronic noise (using discrete NIM standard charge sensitive preamplifiers), we conclude that the measured spatial and spectral performance fulfills 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 3-D CZT drift strip technology within future emerging MBI systems.