Image quality improvements with time-of-flight positron emission tomography for molecular imaging

The renewed interest in time of flight (TOF) PET is being driven by the development of detector technology and the growth of new molecular imaging applications. In this study we performed Monte Carlo simulations to quantify image quality improvements as a function of timing resolution for imaging scenarios that mimic whole body and brain imaging. We implemented an iterative image reconstruction algorithm that incorporated time-of-flight information. Image quality, as measured through contrast and noise metrics, consistently improved with improved timing resolution. We simulated and compared a conventional PET scanner with a TOF-PET scanner with 200 ps timing resolution. For lesions embedded in 40 cm and 20 cm cylindrical objects, lesion contrast improved by a factor of 3.4 and 2.3, respectively. TOF-PET holds the potential for significantly improved imaging over conventional PET scanners of equivalent sensitivity.