Speaker
Description
PET technology has received several improvements in performance due to significant advances in instrumentation and software. Recent trends make use of the time-of-flight (ToF) information to increase the signal-to-noise ratio (SNR) in the reconstructed image and improve the location of the annihilation event. One of the most important components in ToF-PET instrumentation is the scintillation crystal. The development of scintillation crystals is illustrated by the advent of inorganic scintillators with better energy resolution, faster response and higher detection efficiency. Recently, the metascintillator approach has been proposed to overcome the timing resolution limits of the commonly used scintillators. The metascintillator is an engineered composition of small units that combines and optimizes several features in the same scintillator heterostructure. After incident radiation interacts with the metascintillator, a recoil electron is formed and gradually loses energy along its travel path. The scintillator heterostructure follows a probability distribution to share the energy of the radiation interaction with different materials and combine their properties. Therefore, scintillator heterostructure has to be designed considering the range of the recoil electron, which is typically 400 to 500 microns in BGO and LYSO crystals.
In this work, a metascintillator-based PET system was modeled using the GATE Monte Carlo simulations platform and compared against bulk LYSO and BGO PET systems. Several metascintillator thickness values were simulated to determine its equivalence to a bulk BGO crystal in terms of sensitivity, noise equivalent count rate (NECR) and scatter fraction, according to the NEMA guidelines. Only listmode data was used for comparison purposes to avoid the dependence of the image reconstruction algorithm. The main goal of this work is to determine the clinical added value by using metascintillator-based detectors in brain PET imaging.
