Author/Authors :
Amendolia، نويسنده , , S.R and Bisogni، نويسنده , , M.G. and Bottigli، نويسنده , , U. and Ceccopieri، نويسنده , , A. and Delogu، نويسنده , , P. and Dipasquale، نويسنده , , G. and Fantacci، نويسنده , , M.E. and Maestro، نويسنده , , P. and Marchi، نويسنده , , A. and Marzulli، نويسنده , , V.M. and Oliva، نويسنده , , P. and Palmiero، نويسنده , , R. and Pernigotti، نويسنده , , E. and Rosso، نويسنده , , V. and Stefanini، نويسنده , , A. ، نويسنده ,
Abstract :
We report the status of the art of a prototype based on a GaAs pixel detector bump-bonded to a dedicated VLSI chip to be possibly used for imaging in the nuclear medicine field. This device, with a 200 μm thick pixel matrix (64×64 square pixels, 170 μm side), has already been tested with very good results for digital mammography applications (mean energy 20 keV). For more energetic photons, as in nuclear medicine, a 600 μm thick detector has been chosen. Using radioactive sources (241Am, 60 keV and 99mTc, 140 keV photons) we have measured the performance of our prototype in terms of charge collection and detection efficiency of the detector, discrimination capability of the electronics and imaging properties of the whole system. In particular, we have evaluated the spatial resolution properties measuring the Point Spread Function and the imaging capabilities using a home made thyroid phantom. We present also the comparison between these results and those obtained with a traditional gamma camera and the evaluation, made by both experimental measurements and software simulations, of the geometry related to the use of a collimator.
