Monte Carlo simulation of a silicon strip detector response for angiographic applications. First approach. C. Ceballos a, G. Baldazzi b, D. Bollini b, A.E.Cabal Rodríguez a, W. Dabrowski c, A.Días García a, M. Gambaccini d, P. Giubellino e, M. Gombia b, P. Grybos c, M.Idzik c,e, A. Marzari-Chiesa f, L.M. Montaño g, F. Prino h, L. Ramello h, M. Sitta h, K. Swientek c, A. Taibi d, A. Tuffanelli d, R. Wheadon e, P. Wiacek c a CEADEN, Havana, Cuba; b Dipartimento di Fisica dell Università di Bologna and INFN, Bologna, Italy; c Faculty of Physics and Nuclear Techniques, University of Mining and Metallurgy, Cracow, Poland; d Dipartamneto di Fisica dell Università di Ferrara and INFN, Ferrara, Italy; e INFN, Torino, Italy; f Dipartimento di Fisica dell Università di Torino and INFN, Torino, Italy; g CINVESTAV, Mexico City, Mexico, h Dipartimento di Scienze e Tecnologie Avanzate dell Università del Piemonte Orientale and INFN, Alessandria, Italy

First results of Monte Carlo simulation by MCNP transport code of an experimental facility at Bologna S. Orsola hospital for studying the possible application of a X-Ray detection system based on a silicon strip detector on a dual energy angiography. The quasi-monochromatic X-ray beam with the detector in the edge-on configuration has been used to acquire images of a test object at two different energies (namely 31 and 35 keV) suitable for the K-edge subtraction angiography application. As a test object a Plexiglas step wedge phantom was used. It was 40 mm high and 50 mm wide and with a thickness ranging from 10 mm to 40 mm with three 2mm Aluminum layers on it. Four cylindrical cavities, having a 1 mm diameter, have been drilled and filled, with iodated contrast medium, whose concentration varied from 370 mg/ml to 92 mg/ml. Both the profiles obtained from measurements and the images generated with them where reproduced by computer simulation on a first approach to use this technique as an evaluation tool for future developments on the experimental setup ABSTRACT

EXPERIMENTAL SETUP

STRIPS DEAD ZONE Aluminium Layer PMMA 1 mm Iodine Filled Tube Detector characteristics Strip length 10 mm Thickness 300 m Dead region (edge – on config.) 765 m Strip pitch 100 m Strip width 80 m Channels 400 Photo of the upper-left detectors corner MCNP Simulated Geometry

Image obtained from measurements Image obtained from simulation Conc(I) = 370 mg/ml E=31.5 KeV

Conc(I) = 370 mg/ml E=35.5 KeV Image obtained from measurements Image obtained from simulation

Conc(I) = 370 mg/ml K-edge subtraction image: ln(image35.5) - ln(image31.5) Image obtained from measurements Image obtained from simulation

Conc(I) = 185 mg/ml K-edge subtraction image: ln(image35.5) - ln(image31.5) Image obtained from measurements Image obtained from simulation

Conc(I) = 92 mg/ml K-edge subtraction image: ln(image35.5) - ln(image31.5) Image obtained from measurements Image obtained from simulation