IMAS, Unique TB-PET System with DOI and TOF: First Clinical Tests

Total Body (TB) - PET is becoming more popular with about 50 systems already installed worldwide. TB-PET are characterized by axial coverages ranging <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$100-200 ~\text{cm}$</tex>, including timing capabilities in the range of 180-250 ps. These systems have shown great potential in several application fields, due to their significantly increased sensitivity (both physical and clinical), and to the possibility to study correlations between distant organs in a single exam. However, available TB-PET are very expensive and they not enable depth of interaction (DOI) information. In this work we present a unique TB-PET based on semi-monolithic LYSO scintillators. The system has 70 cm axial coverage thus allows to image most relevant organs, combined with DOI capabilities improving spatial resolution performance towards the edge of the field of view. We have compared our current results with state-of-the-art TB-PET scanners, showing a factor 2-3 better spatial performance at 30 cm off-radial positions. First clinical images have been already acquired. The reconstructed images also pinpoint the advantages of improved impact determination (both monolithic and DOI directions), better delineating small and multi-centric tumors.