Experimental validation of a coincidence time resolution metric including depth-of-interaction bias for TOF-PET.

Experimental validation of a coincidence time resolution metric including depth-of-interaction bias for TOF-PET.
Phys Med Biol. 2020 Jul 21;:
Authors: Loignon-Houle F, Toussaint M, Lee MS, Cates JW, Lecomte R
Abstract
Depth-of-interaction (DOI) variability of annihilation photons is known to be a source of coincidence time resolution (CTR) degradation for fast TOF-PET detectors. An analytical model was recently proposed to explicitly include the DOI time bias separately from variance-related statistical factors, such as scintillation photon emission and photosensor jitter, in the CTR evaluation. In the present work, an experimental validation of this new model is provided. An unconventional signal readout configuration was used to magnify the DOI bias with 20 mm long LYSO:Ce crystals. In a head-to-head orientation of the crystals, simulations performed using the metric with DOI bias exhibited a much better agreement (within 21 ps) with the experimentally measured CTR of 413 ± 8 ps FWHM, whereas simulations without DOI bias underestimated the CTR by 138 ps. The metric including DOI bias was shown to also be effective at predicting the CTR of the head-to-head setup (without DOI information) using data from a DOI-collimated experimental setup (with partial DOI information). With the development of new low-variance ultra-fast detectors, the DOI timing blur will become increasingly important and will need to be taken into account in anal...

Source: Physics in Medicine and Biology - July 20, 2020 Category: Physics Authors: Loignon-Houle F, Toussaint M, Lee MS, Cates JW, Lecomte R Tags: Phys Med Biol Source Type: research