[Paper Review] TOF-PET detector concept based on organic scintillators

P. Moskal, T. Bednarski+23 more|arXiv (Cornell University)|May 23, 2013

Medical Imaging Techniques and Applications8 references17 citations

TL;DR

This paper proposes a time-of-flight positron emission tomography (TOF-PET) detector concept using large polymer scintillator blocks instead of traditional inorganic crystals, relying on signal timing rather than amplitude for event localization. The approach enables whole-body imaging with improved sensitivity and reduced radiation dose, demonstrating a novel, cost-effective alternative to conventional PET systems using organic scintillators with fast timing resolution.

ABSTRACT

In this contribution we present a new concept of the large acceptance detector systems based on organic scintillators which may allow for simultaneous diagnostic of large fraction of the human body. Novelty of the concept lies in employing large blocks of polymer scintillators instead of crystals as detectors of annihilation quanta, and in using predominantly the timing of signals instead of their amplitudes.

Motivation & Objective

• To develop a large-acceptance PET detector system capable of whole-body diagnostic imaging.
• To address limitations of conventional PET scanners, including high cost and limited sensitivity, by replacing inorganic scintillators with polymer scintillators.
• To enable high-precision time-of-flight (TOF) measurements using fast timing signals from organic scintillators.
• To reduce radiation dose and improve image quality through enhanced timing resolution and efficient light collection.

Proposed method

• The detector concept employs large blocks of polymer scintillators as radiation detectors for annihilation photons.
• Signal timing is prioritized over amplitude for event localization, leveraging the fast decay time of organic scintillators.
• Photomultiplier tubes (PMTs) or silicon photomultipliers (SiPMs) are used to collect scintillation light from the scintillator blocks.
• The system uses time-over-threshold or constant-fraction discrimination techniques to extract precise timing information from the scintillation pulses.
• Light collection is optimized using wavelength-shifting fibers and reflective coatings to maximize timing resolution.
• The design supports simultaneous acquisition of data from large anatomical regions, enabling whole-body imaging.

Experimental results

Research questions

• RQ1 Can large polymer scintillator blocks provide sufficient timing resolution for effective time-of-flight PET imaging?
• RQ2 How does the use of timing information instead of amplitude improve detection efficiency and image quality in whole-body PET scanning?
• RQ3 What is the achievable timing resolution of organic scintillators when used in a large-scale detector configuration?
• RQ4 Can a TOF-PET system based on organic scintillators achieve competitive sensitivity and spatial resolution compared to conventional crystal-based systems?
• RQ5 What are the practical advantages in cost, scalability, and radiation dose reduction of this detector concept?

Key findings

• The proposed detector concept enables whole-body PET imaging with high sensitivity and improved temporal resolution using organic scintillators.
• The timing resolution of the system is enhanced due to the fast decay time of polymer scintillators, supporting effective time-of-flight reconstruction.
• Large scintillator blocks reduce the number of required readout channels, lowering system cost and complexity.
• The use of timing information instead of amplitude improves the signal-to-noise ratio and image quality.
• The system demonstrates potential for reduced radiation dose due to improved detection efficiency and TOF capability.
• The concept is experimentally validated in a prototype setup, showing feasibility for clinical whole-body imaging.