Quantitative YAP-(S)PET small animal scanner: preliminary results

We have successfully built and characterized small animal PET scanner based on 4 rotating planar detector heads. Each detector module is composed of a matrix of 400 YAP:Ce finger crystals (2×2×30 mm³ each) directly coupled to position sensitive photomultipliers (Hamamatsu R2486-06). By applying two high resolution collimators to two opposite detectors we realised an integrated PET-SPECT scanner for small animals. At present, at the Department of Experimental and Clinical Medicine of the University of Ferrara, the scanner is employed in small animal SPECT studies with ^99mTc labeled radiotracers dedicated to obtain quantitative activity measurement in region of interest (ROI) directly from a reconstructed image of a in-vivo rat, with respect to the traditional ex-vivo measurement of activity with gamma counters. To achieve this goal, the scanner was calibrated referring it to a Isodose dose calibrator based on Geiger-Muller counters which previously underwent an absolute calibration with a known activity source. Preliminary results on quantitative tomographic heart perfusion and planar heart biokinetics studies are reported.