About this Research Topic
Positron emission tomography (PET) is the most sensitive imaging modality, commonly used to detect the spread of cancer, monitor treatment plans, study brain disorders and heart diseases, support drug development, and image metabolic processes in the body, among other uses. By measuring the time-of-flight (TOF) of the two 511-keV annihilation gamma-rays, the origin of the event can be estimated, supporting image reconstruction procedures while enabling significant signal-to-noise (SNR) gains compared to non-TOF-capable devices. Current TOF-PET scanners exhibit a TOF resolution of 180 to 400 ps full width at half maximum (FWHM), which constrains the annihilation event within a region of 3-6 cm along the line of response (LOR).
To push through the barrier of 100 ps toward 10 ps coincidence time resolution, the entire radiation detector chain must be optimized. This includes a deep understanding of the underlying physics and physical limits of each element composing the detection chain, accurate modeling to guide detector development, the exploration of new materials with faster response times, enhanced photodetector technology with low noise and high photodetection efficiency, and novel approaches on the implementation of ultrafast TOF kernels on the image reconstruction. While this topic focuses on improving radiation detectors for TOF-PET, it is not limited to this application. Other areas, such as computed tomography (CT) and prompt gamma imaging in hadron therapy, have specific detector requirements and operate at different energy ranges from ~10 keV up to ~6 MeV X-rays/gamma-rays. However, they equally benefit from having an accurate timestamp in the hundreds of picosecond regime.
For this research topic, contributions are expected to address one of the following areas related to the advancement in TOF-based medical imaging:
• Development of new or revival of overlooked scintillators / light-emitting materials for medical imaging detectors.
• Emerging photodetector technologies for medical imaging (SPAD, LGAD, SiPM, PMT, MCP-PMT).
• New readout electronics and ASIC R&D for medical imaging.
• Exploiting prompt-light emission in hybrid scintillators to boost CTR.
• Exploring TOF-driven data to boot SNR and to create attenuation maps for PET image correction
• Simulation or measurement of the influence of the depth of interaction and light transport inside the scintillator on the TOF resolution and
possible correction methods with a focus on the achievable time resolution.
• Multi-channel prototypes and performance evaluation toward a full system.
• Advanced analysis (eg. AI) applied to light-based radiation detectors for medical imaging.
To push through the barrier of 100 ps toward 10 ps coincidence time resolution, the entire radiation detector chain must be optimized. This includes a deep understanding of the underlying physics and physical limits of each element composing the detection chain, accurate modeling to guide detector development, the exploration of new materials with faster response times, enhanced photodetector technology with low noise and high photodetection efficiency, and novel approaches on the implementation of ultrafast TOF kernels on the image reconstruction. While this topic focuses on improving radiation detectors for TOF-PET, it is not limited to this application. Other areas, such as computed tomography (CT) and prompt gamma imaging in hadron therapy, have specific detector requirements and operate at different energy ranges from ~10 keV up to ~6 MeV X-rays/gamma-rays. However, they equally benefit from having an accurate timestamp in the hundreds of picosecond regime.
For this research topic, contributions are expected to address one of the following areas related to the advancement in TOF-based medical imaging:
• Development of new or revival of overlooked scintillators / light-emitting materials for medical imaging detectors.
• Emerging photodetector technologies for medical imaging (SPAD, LGAD, SiPM, PMT, MCP-PMT).
• New readout electronics and ASIC R&D for medical imaging.
• Exploiting prompt-light emission in hybrid scintillators to boost CTR.
• Exploring TOF-driven data to boot SNR and to create attenuation maps for PET image correction
• Simulation or measurement of the influence of the depth of interaction and light transport inside the scintillator on the TOF resolution and
possible correction methods with a focus on the achievable time resolution.
• Multi-channel prototypes and performance evaluation toward a full system.
• Advanced analysis (eg. AI) applied to light-based radiation detectors for medical imaging.
Keywords: time-of-flight positron emission tomography (TOF-PET), fast timing, coincidence time resolution (CTR), signal-to-noise ratio (SNR), prompt photon emission, photodetector, scintillating crystal, depth-of-interaction (DOI)
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
