Monte Carlo feasibility study for in vivo small animals beta detection: from beta to Cerenkov luminescence imaging

In this work we investigated using Monte Carlo simulations the feasibility of beta imaging of small animals with CLI, direct and indirect beta detection and bremsstrahlung using beta minus emitters. This study shows pro and cons of the different physical approaches for beta emitter imaging for small animals. Monte Carlo simulations were implemented using GAMOS plugin for GEANT4 considering a slab of mouse muscle and a radioactive source (32P or 90Y) placed at 0.5 mm depth. We found that direct beta detection and CLI are best approaches in term of resolution while the use of a thin scintillator increases the signal but the spatial resolution is degraded. Bremsstrahlung presents lower signal and it does not represent the best choice in small animal imaging. We conclude that CLI is a more flexible approach for in vivo beta minus emitter imaging.