Development of TOF-PET using Cherenkov radiation

We proposed a new concept of TOF-PET (Time-of-Flight Positron Emission Tomography) using Cherenkov radiation. Basic experiments revealed a timing resolution of 170 ps, but the detection efficiency was less than those of the conventional BaF2 scintillators. Through simulation studies, we confirmed that the spatial resolution and the S/N ratio of the images reconstructed with TOF information were 1.5 and 3 times better, respectively, than they were without TOF information, when we adopted the FP (Forward Projection) method combined with the ML-EM (Maximum Likelihood Expectation Maximization) algorithm as an image reconstruction algorithm. Consequently, we concluded that TOF-PET using Cherenkov radiation is a promising candidate for next-generation PET. We concluded that PWO (PbWO4) is the best Cherenkov radiator from the viewpoint of detection efficiency. Additionally, we found that the Monte Carlo algorithm was able to generate images having error bars and thus to make quantitative diagnoses possible. (author)