BLUISH – Scalable TOF-PET technology using Cherenkov light at BGO

In this project, named Bluish, we propose developing new affordable and high-performance PET detector technology with accurate 3D impact positioning and precise Time of Flight (TOF) capabilities based on Bismuth Germanate (BGO) scintillators.

BGO has a price that can be a factor 2-3 times cheaper than lutetium-based ones. BGO has high density, short attenuation length for 511 keV photons and high photo-fraction, thus partially reducing the undesired Compton contributions to the energy spectra. Furthermore, BGO does not emit natural radiation, minimizing possible false coincidences. However, BGO has reduced timing capabilities since the dominant component (~92%) of BGO’s decay time is large and presents a light yield 4 times smaller than lutetium-based scintillators. Our main goal is to develop a scalable detector able to exploit such 8.2% fast scintillation, as well as the low Cherenkov yield present in BGO to boost the TOF performance and thus, open the way to reintroduce BGO scintillators in PET.

In this proposal we specifically aim for <400 ps CTR and accurate 3D positioning capabilities (3 mm spatial and 5 mm depth of interaction resolution) using 15 mm thick BGO pseudo-slabs. The result of this work will provide the first scalable BGO-based TOF-PET detector able to achieve the same or even better effective sensitivity than state-of-the-art scanners thus, facilitating high performance clinical PET with 4–5-fold lower scintillation material cost (due to BGO volume and price).