Simulation studies to understand sensitivity and timing characteristics of an optical property modulation-based radiation detection concept for PET.

Simulation studies to understand sensitivity and timing characteristics of an optical property modulation-based radiation detection concept for PET.
Phys Med Biol. 2020 Jul 24;:
Authors: Tao L, Jeong D, Wang J, Adams Z, Bryan P, Levin CS
Abstract
The concept of using the modulation mechanisms of a material's optical properties for annihilation photon detection has been proposed as a potential method to significantly improve the coincidence time resolution (CTR) of positron emission tomography (PET) detectors. However, the possibility of detecting individual 511 keV photons with largely improved CTR using the proposed detection method has not yet been demonstrated, either experimentally or theoretically. In addition, the underlying physical picture of the optical modulation effects induced by annihilation photons has not been fully understood. In this work, we perform simulation studies including generation of the annihilation photon-induced ionization energy deposition trajectory, estimation of the charge carrier cascade time and temporal variance, simulation of the distribution of ionization-induced charge carrier density, and calculation of the strength of the modulation of two optical parameters: the absorption coefficient and the refractive index, as well as evaluation of the resulting optical intensity and phase change experienced by a probe laser beam. Our simulation results show that the average absorption coefficient modulati...

Source: Physics in Medicine and Biology - July 23, 2020 Category: Physics Authors: Tao L, Jeong D, Wang J, Adams Z, Bryan P, Levin CS Tags: Phys Med Biol Source Type: research