Development of a Prototype Detector for Use in Scintimammography Imaging

In this paper, we report the development of a prototype for a new kind of detector intended for scintimammography imaging. Traditional photon counting information is available; moreover, digital words representing the amplitude of each event and suitable image elaboration methods significantly enhance the detector capabilities. The prototype detector is composed of a collimator and four imaging modules. Each module is composed of an 8×8 sensing array of 2×2 mm silicon PIN photodiode pixels, coupled to a CsI(Tl) scintillator and custom readout electronics. The sensor is fixed to an Al2O3 printed circuit board. Eight readout mixed analog-digital integrated circuits, wire bonded to the sensor pixels, provide analog signal conditioning, A/D conversion, self-triggered acquisition and bidirectional serial data transfer. Digital signals are routed out so that each module can be attached to a main board with suitable control logic for overall detector management. PC-based supervision of the detector is accomplished through an USB 2.0 interconnection using an easy-to-use graphical user interface. The purpose of the prototype is to test the approach and the chosen architecture; all its elements have been designed in order to permit the construction of the final detector with a significantly larger sensing area.