BOLD-PET: Application of the technologies of neutrino and dark matter experiments at medical imaging

© AG Weinheimer
© AG Weinheimer

The aim of the BOLD-PET project is to develop a fast-response, high-efficiency
gamma detector with fine grained spatial resolution for positron emission tomography (PET) based on recent developments using the liquid TriMethyl Bismuth (TMBi). This liquid with a bismuth mass fraction of more than 80% allows for a very efficient and
accurate detection of 511 keV photons originated from positron annihilation. Bismuth has the highest nuclear charge (Z = 83) and thus the largest photoelectric cross section of all stable isotopes. The gamma energy of 511 keV is transferred to electrons in this material in nearly 50 % of the cases through the photoelectric effect. Both the Cherenkov light emitted by the resulting relativistic photo-electron and the secondary charge carriers produced during multiple scattering interactions are detected in a liquid ionisation chamber, supplemented by photodetectors. Based on previous studies of liquid TMBi, we
intend to develop and evaluate a novel PET detector with simultaneous detection of Cherenkov light and ionisation in a common effort of four research partners:
The expertise of the existing French CaLIPSO group (CEA-IRFU, CNRS-LAL) will be supplemented by the expertise on high-resolution PET imaging and detector development of Prof. Dr. Klaus Schäfers from EIMI and the WWU Faculty of Medicine, and ultra-purification as well as light and charge detector expertise by our group. The main objective of this collaborative project is to develop a novel detector system for PET imaging (e.g. human brain PET, small animal PET) with a projected efficiency of 30%, high spatial precision of 1mm^3, and high time of flight resolution of 100 ps (FWHM).