Simultaneous acquisition of K-edge subtraction images using a pnCCD

The recent developments in the semiconductor detector technology, in particular the pnCCD, makes it possible to measure energy and position of X-rays after scattering with the specimen at the same time. An interesting application for such a device is the measurement of a contrast medium in vivo or in vitro using the K-edge subtraction method. The pnCCD detectors developed at the semiconductor laboratory of Max-Planck-Institute are well suited for such applications. They show very high quantum efficiencies in the energy range between 1–15 keV and can be used in a single photon counting mode. The pnCCD used for these experiments comprises 256×256 pixels with a pixel size of 75×75 μm² and is equipped with a special analog frame buffer for high speed applications.