Results about imaging with silicon strips for Angiography and Mammography

Abstract

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 Xray 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.

K-edge digital subtraction imaging based on a dichromatic and compact x-ray source

“…Images of the phantom have been acquired at the two energies of the dichromatic beam using a detection system capable of single photon counting. The detector is a prototype (Baldazzi et al 2003a(Baldazzi et al , 2003b(Baldazzi et al , 2003c) based on an array of 384 silicon microstrips equipped with read-out electronics of 6 RX64 ASICs: each strip is 1 cm long, has a pixel pitch of 100 µm and a depth of 300 µm. We used the detection system in edge-on configuration, i.e putting the microstrips parallel to the incoming beam.…”

Contrast cancellation technique applied to digital x‐ray imaging using silicon strip detectors

“…Mammographic imaging experiments were performed in 2002 and 2003 at the quasi-monochromatic beam facility located at University of Ferrara; preliminary results were previously reported. 19,20 The dual-energy analysis procedure was applied to the data obtained from the experiment as well as to those obtained from a Monte Carlo simulation of the experimental setup. For the simulation the particle transport code MCNP-4C was used.…”