# New optical Monte Carlo simulation tools for nuclear medicine

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2021 · $303,755

## Abstract

Project Summary/ Abstract
 Timing resolution is one of the most important features of current and future radiation detectors for
diagnostic and therapeutic imaging. In positron emission tomography (PET), it has drastically improved image
quality through time-of-flight (TOF) with a resolution of 350-500 ps that allows for the localization of positron
annihilations– a direct measure of the activity distribution in the patient, with an uncertainty of 5-7.5 cm.
Further improvement in image contrast could be obtained, with the ultimate goal of directly reconstructing the
positron annihilation through an ambitious target of 10 ps timing resolution. Improving the detector timing
requires the light transport to be thoroughly optimized, which can only be done through accurate Monte Carlo
simulation. This proposal will develop accurate optical simulation tools for nuclear medicine detectors
and will apply them to the design of fast detectors for TOF PET.
 The opensource software GATE and Geant4 constitute the main simulation platform in nuclear imaging
and therapy. It includes optical transport in scintillators, but the models used to describe the light reflecting
on the scintillator surfaces are highly inaccurate. We have developed and integrated into GATE a new optical
model, the “LUT Davis model” that addresses this limitation. This work, supported by an NIH R03 grant,
demonstrated the feasibility of accurate scintillator optical modeling and opened the possibilities of using
simulations for detector timing studies. Of particular interest are Cerenkov photons that are being investigated
to improve timing resolution as low as 10 ps, which will require more advanced simulation tools.
 We will first develop and freely distribute computational tools to generate custom optical surface LUTs
This aim is expected to have a strong impact on the nuclear imaging community where new detectors are
being designed for future generations of scanners. Second, we will specifically develop optical models for
photon timing studies, with the goal of establishing a comprehensive simulation framework for detector timing
optimization. Third, we will apply our advanced Monte Carlo simulation tools to optimize the use of Cerenkov
photons for a cost-effective BGO TOF PET detector and to develop the first semiconductor TOF PET
detector. With these timing studies, we will tackle one of the most important challenges in PET
research, which has the potential to transform PET instrumentation.

## Key facts

- **NIH application ID:** 10058840
- **Project number:** 5R01EB027130-03
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Emilie Roncali
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $303,755
- **Award type:** 5
- **Project period:** 2019-03-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10058840

## Citation

> US National Institutes of Health, RePORTER application 10058840, New optical Monte Carlo simulation tools for nuclear medicine (5R01EB027130-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10058840. Licensed CC0.

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