Autori: N. Auricchio, G.D. Domenico, L. Milano, R. Malaguti, G. Ambrosi, M. Ionica, E.Fiandrini, G. Zavattini

Editorial: IEEE Transactions on Nuclear Science, 57, Iss.5, p.2424-2436, 2010.

Rezumat:

In this paper we propose a new scanner for small animal positron emission tomography (PET) based on stacks of double sided silicon detectors. Each stack is composed of 40 planar detectors with dimension 60mmx60mmx1mm and 128 orthogonal strips on both sides to read the two coordinates of interaction, the third being the detector number in the stack. Multiple interactions in a stack are discarded. In this way we achieve a precise determination of the first interaction point of the two 511 keV photons. The price to pay is an efficiency reduction for each stack of about 50%. The reduced dimensions of the scanner also improve the solid angle coverage resulting in a high sensitivity. Preliminary results were obtained with the MEGA prototype tracker. Here, we report on the results obtained with double sided silicon prototype detectors, manufactured by ITC-FBK, having an active area of 3cm x 3cm and a strip pitch of 500um. Two different strip widths of 300um and 200um, and two thicknesses of 1mm and 1.5mm, equipped with 64 orthogonal p and n strips on opposite sides were read out with the VATAGP2.5 ASIC, a 128channel „general purpose” charge sensitive amplifier. We describe the experimental setup, the measurements and the results in terms of spatial resolution, spectral and timing performances obtained with the prototype detectors.

Cuvinte cheie: Gamma-ray detectors, PET, Small animal imagers