CDTE Detectors for Simultaneous Emission/Transmission CT

A simultaneous Emission/Transmission Computed Tomography (ETCT) system possesses theadvantages of both SPECT and CT by offsetting the individual weakness of each. However, thesuccessful development of ETCT machine must include improved spatial resolution, which currently islimited by the X-ray and gamma-ray detector systems used. Scintillation cameras used in SPECT areessentially at their limit of spatial resolution. Silicon photodiode detectors used in CT are limited bysensitivity. The most promising detectors for this application are solid state detectors like HPGe andCdTe. The cryogenic requirement of HPGe makes CdTe a unique candidate for the ETCT innovation.Our recent process with CdTe x-ray and gamma-ray detectors is very encouraging, an energy resolutionof l.7KeV FWHM has been observed for 57Co (l22KeV). Further research into this promising systemhas high potential of producing a new detector technology with better performance, which could be thebasis for a future generation of medical imaging instruments like ETCT. The goal of this Phase I programis to demonstrate the feasibility of using the semiconductor CdTe in ETCT instruments.