Novel bio-compatible tracers for Positron Emission Particle Tracking

To study the flow of objects (tracers) in opaque flow processes, the PEPT (positron emission particle tracking) technique is utilized. The PEPT technique is based on the same principle of PET (positron emission tomography) which detects the characteristic back-to-back gamma pairs caused by positron-electron annihilation. The annihilation takes place within a few millimeters around the tracers labeled with positron-emitting isotopes. PEPT allows locating the droplets or ice particles (depending on the surrounding temperature) in high spatial and temporal resolutions. This makes the technique promising in a number of medical applications that require observation of fast transient phenomena e.g. heart hemodynamics, lungs aerodynamics etc. However, the tracers utilized so far are based on activated solid particles of a micrometric size which are hardly removed in-vivo after the test. In this contribution, we propose new tracers based on frozen radioactive solutions rather than activated solids