Results about imaging with silicon strips for angiography and mammography

We present results obtained with a single photon counting system consisting of 384 silicon microstrips of 100 micron pitch equipped with 6 RX64 ASICs. The ASIC includes a charge preamplifier, a shaper, a discriminator and a 20‐bit counter for each of its 64 channels. The energy resolution of the system has been measured in the range from 8 keV to 32 keV using fluorescence X‐ray lines from several targets, using either an Am‐241 source or an X‐ray tube. Then, the efficiency of the system has been determined using the specially developed quasi‐monochromatic X‐ray beams in the energy range 18–36 KeV. Good efficiency has been obtained in the edge‐on configuration, which is more suitable for the intended applications. The spatial resolution of the system has been verified using a special microfocus X‐ray tube equipped with capillaries. Finally, images of angiographic and mammographic test objects have been obtained with dual energy X‐ray beams and have then been processed with the dual energy subtraction technique. In particular, the contrast for the angiographic test object has been evaluated for different concentrations of an iodate solution injected into 1 mm and 2 mm diameter vessels. Further developments, including a double threshold version of the ASIC, are also discussed