Georgios Konstantinou

Swiss Federal Institute of Technology in Lausanne | EPFL · Photovoltaics and Thin Film Electronics Laboratory

Pixelated scintillators are commonly used for gamma radiation detection in PET scanners. Dimensions, surface treatment and reflector thickness affect the resolution and sensitivity of the detector and increase the signal to noise ratio. Pixel arrays fabrication is laborious and expensive, while by including non-scintillating material the active are...

Scintillation detector development is an active field of research, especially for its application to the medical imaging field and in particular to the positron emission tomography (PET). Effective sensitivity and signal to noise ratio in PET are greatly enhanced when improving detector timing capabilities: the availability to provide time-of-fligh...

The signal-to-noise ratio in Positron Emission Tomography (PET) improves with precise timing resolution. PET systems enabling the capability of Time-of-Flight (ToF) are nowadays available. This study assesses various data configurations, comparing the obtained timing performances applicable to ToF-PET systems. Different readout configurations were...

This study focuses on advancing metascintillators to break the 100 ps barrier and approach the 10 ps target. We exploit nanophotonic features, specifically the Purcell effect, to shape and enhance the scintillation properties of the first-generation metascintillator. We demonstrate that a faster emission is achievable along with a more efficient co...

The signal-to-noise ratio in Positron Emission Tomography (PET) improves with precise timing resolution. PET systems enabling the capability of Time-of-Flight (ToF) are nowadays available. This study assesses various data configurations, comparing the obtained timing performances applicable to ToF-PET systems. Different readout configurations were...

In this study, we propose and examine a unique semimonolithic metascintillator (SMMS) detector design, where slow scintillators (BGO or LYSO) are split into thin slabs and read by an array of SiPM, offering depth-of-interaction (DOI) information. These are alternated with thin segmented fast scintillators (plastic EJ232 or EJ232Q), also read by sin...

The Digitizer Unit plays an important role in modeling using Geant4 Application for Tomographic Emission (GATE), a Geant4-based platform used for numerical simulations in medical imaging and radiotherapy. It simulates the response of the photodetection components using a sequence of analytical and semi-analytical models. The Digitizer Unit was writ...

p>Positron Emission Tomography (PET) imaging quality hinges on precise timing resolution, which is especially critical for Time-of-Flight (ToF) PET systems. This study assesses various data acquisition technologies to compare their timing performances for ToF-PET applications. Different read-out approaches are evaluated to extract data from Silicon...

p>Positron Emission Tomography (PET) imaging quality hinges on precise timing resolution, which is especially critical for Time-of-Flight (ToF) PET systems. This study assesses various data acquisition technologies to compare their timing performances for ToF-PET applications. Different read-out approaches are evaluated to extract data from Silicon...

p>In time-of-flight positron emission tomography (TOF-PET), the timing capabilities of the scintillation-based detector play an important role. An approach for fast timing is using the so-called metascintillators, which combine two materials leading to the synergistic blending of their favourable characteristics. An added effect for BGO-based metas...

In time-of-flight positron emission tomography (TOF-PET), the timing capabilities of the scintillation-based detector play an important role. An approach for fast timing is using the so-called metascintillators, which combine two materials leading to the synergistic blending of their favorable characteristics. An added effect for BGO-based metascin...

p>The working principle of metascintillators is based on sharing the energy of an impinging gamma ray between their composing materials. Such can be a dense crystal such as LYSO or BGO to maximize the gamma stopping potential and a fast organic or inorganic compound such as BC-422, EJ232 or BaF2 for its light production kinetics. In this work we lo...

p>The working principle of metascintillators is based on sharing the energy of an impinging gamma ray between their composing materials. Such can be a dense crystal such as LYSO or BGO to maximize the gamma stopping potential and a fast organic or inorganic compound such as BC-422, EJ232 or BaF2 for its light production kinetics. In this work we lo...

Scintillation detector is the standard approach for positron emission tomography (PET). Effective sensitivity and signal to noise ratio in PET are greatly enhanced when improving detector timing capabilities, due to the availability of time-of-flight information. However, physical barriers related to the characteristics of available organic and ino...

p>Recent trends in Positron Emission Tomography (PET) use the time-of-flight (ToF) information in the image reconstruction process to improve the signal-to-noise ratio and the positioning of the annihilation event. One of the components that most contributes to the accuracy of the ToF-PET is the scintillation crystal. The metascintillator approach...

p>Recent trends in Positron Emission Tomography (PET) use the time-of-flight (ToF) information in the image reconstruction process to improve the signal-to-noise ratio and the positioning of the annihilation event. One of the components that most contributes to the accuracy of the ToF-PET is the scintillation crystal. The metascintillator approach...

We report in this paper on the Fast Timing in Medical Imaging workshop, (Valencia, Jun2 2022). The workshop gathered 104 attendees from all over the world, with representatives from the academic and industrial sectors. During three very dense days, nuclear medicine physicians, radiologists, oncologists, immunologists and biologists have debated wit...

p>Presentation of simulation results on a new metascintillator concept (semi-monolithic) combining state-of-the art timing resolution and depth-of-interaction, with the application of neural networks to provide accurate estimations of energy sharing and energy of interaction.</p

p>Presentation of simulation results on a new metascintillator concept (semi-monolithic) combining state-of-the art timing resolution and depth-of-interaction, with the application of neural networks to provide accurate estimations of energy sharing and energy of interaction.</p

p>Positron emission tomography scanners are commonly characterized by their photon sensitivity. Scanner design often requires Monte Carlo simulations to probe different geometries and materials. However, the computational load of such simulations can be significant and costly. Furthermore, the applicability of the Monte Carlo approach in optimizati...

p>Positron emission tomography scanners are commonly characterized by their photon sensitivity. Scanner design often requires Monte Carlo simulations to probe different geometries and materials. However, the computational load of such simulations can be significant and costly. Furthermore, the applicability of the Monte Carlo approach in optimizati...

Objective: Time-of-flight PET is the next frontier in improving the effective sensitivity. To achieve superior timing for time-of-flight positron emission tomography, combined with high detection efficiency and cost-effectiveness, we have studied the applicability of BaF2 in metascintillators driven by the timing of cross-luminescence photon produ...

p>In time-of-flight positron emission tomography (TOF-PET), the timing capabilities of the scintillation-based detector play an important role. An approach for fast timing is using the so-called metascintillators, which combine two materials leading to the synergistic blending of their favourable characteristics. An added effect for BGO-based metas...

p>In time-of-flight positron emission tomography (TOF-PET), the timing capabilities of the scintillation-based detector play an important role. An approach for fast timing is using the so-called metascintillators, which combine two materials leading to the synergistic blending of their favourable characteristics. An added effect for BGO-based metas...

p>Preprint second review submission</p

p>Preprint second review submission</p

Nuclear medicine probes turned into the key for the identification and precise location of sentinel lymph nodes and other occult lesions (i.e., tumors) by using the systemic administration of radiotracers. Intraoperative nuclear probes are key in the surgical management of some malignancies as well as in the determination of positive surgical margi...

We report on the progress on a first generation of realistic size metascintillators for time-of-flight PET. These heterostructures combine dense LYSO or BGO plates, interleaved with fast scintillator layers producing a bunch of prompt photons from the energy leakage of the recoil photoelectric electron. From a Geant4 simulation of the energy sharin...

Complex scintillating heterostructures, called metascintillators, have shown the potential to break the trade-off between high stopping power and good timing resolution beyond the golden standard of LYSO. However, the combination of materials that share the gamma interactions in a stochastic, event-by-event case, with different light yield, require...

NA62 experiment Straw tracker frontend board serves as a gas-tight detector cover and integrates two CARIOCA chips, a low cost FPGA (Cyclon III, Altera) and a set of 400Mbit/s links to the backend. The FPGA houses 16 pairs of sub-nanosecond resolution TDCs with derandomizers and an output link serializer. Evaluation methods, including simulations,...