YAP-(S)PET Small Animal Scanner: Quantitative Results.

At present, at the Dept of Experimental and Clinical Medicine of the University of Ferrara, the YAP-(S)PET scanner is employed in small animal SPECT studies, with 99mTc labelled radiotracers, dedicated to obtain quantitative activity measurements in a region of interest (ROI) directly from a reconstructed image of a rat, with respect to the traditional ex-vivo measurements 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 various certified activity sources. The calibration factor K was defined as the ratio between the activity measured with the Isodose (MBq) and the image count rate (cps). With the calibrated scanner we compared results of activity measurements from images of whole-rat heart acquisitions vs explanted heart. We find that whole-rat quantitative precision is within 3.2% considering 9% attenuation in the rat tissue