MPRS: Medipix parallel readout system for angiography digital imaging

A fast readout system for a low noise CMOS pixel chip, working in single photon counting mode (Medipix2) has been developed for digital angiography applications. Each chip has an active area of about 2 cm/sup 2/, with 256/spl times/256 square pixels 55 /spl mu/m side size, and can be bump bonded to Si or GaAs for direct charge conversion of incoming photons. The system permits the parallel readout of up to 8 chips at a rate of at least 25 frames/s, to allow real time X-ray imaging of contrast medium flowing in blood vessels. The readout electronics is PCI bus-based and consists of two boards, the motherboard directly interfacing the chip for settings and data flow, and the PCI board linking the motherboard to the bus. Dedicated software has been developed to test each single pixel, set configuration patterns and perform data transfer. With parallel readout transfer rate up to 64 MByte/s has been achieved.