Project Details
Projekt
Bismuth Organic Liquid Detector with Cherenkov Light and Charge Readout for Positron Emission Tomography
Subject Area
Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
Medical Physics, Biomedical Technology
Medical Physics, Biomedical Technology
Term
from 2018 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 406703021
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. Excellent imaging resolution is anticipated with the proposed detector by cancelling out Depth Of Interaction effects while allowing for placement of the detector close to the body which is increasing the detector’s solid angle. The TMBi’s coincidence photoelectric efficiency is the highest available, with twice the value of LSO/LYSO crystals. The new detector should be able to use accurate time-of-flight (TOF) information through Cherenkov light detection in order to improve the contrast of the reconstructed image. To achieve a breakthrough in this challenging project, 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 (WWU-EIMI group), and ultra-purification as well as light and charge detector readout (WWU-PHYSICS group), both from University of Münster. 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). In order to achieve these objectives the project will focus on the following work areas: (1) ultra-purification of TMBi and further characterisation of TMBi for gamma radiation detection, (2) development of an ionisation detector prototype, (3) study of the Cherenkov photon detection in liquid TMBi, (4) Monte Carlo simulation and image reconstruction of a full PET scanner employing the new technology, and (5) evaluation of a final PET detection demonstrator, merging charge and optical readout.
DFG Programme
Research Grants
International Connection
France
Partner Organisation
Agence Nationale de la Recherche / The French National Research Agency
Cooperation Partners
Dr. Dominique Breton; Dr. Viatcheslav Sharry
