Single Photon Imaging with Electronic Collimation

A unique 4×4 germanium detector array has been fabricated to image single photon emitters. Collimation is achieved electronically from a sequential interaction of the emitted radiation between the germanium detector and a scintillation camera. An iterative reconstruction algorithm has been used to remove multiplexing in the acquired counts, thereby producing a conical projection image from multiple views. Computer simulation studies indicate that even though the degradation in signal to noise ratio during the demultiplexing step would reduce the sensitivity by about a factor of two, a large gain in sensitivity over conventional SPECT systems would result from electronic collimation.