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 8x8 sensing array of 2x2mm 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