Anuncio de seminario

The benefits of ultra-fast time-of-flight (TOF) measurement in positron emission tomography (PET) imaging can be considerable, from higher sensitivity, reduction of the radioactive dose to the patient and possibilities of novel scanner geometries without full angular patient coverage. These benefits rely on detectors of the TOF-PET scanner having the best possible coincidence time resolution (CTR) to time tag the annihilation photons emitted by the radiotracer injected to the patient, and thus localize the emission points with enhanced precision. This has motivated extensive efforts from many groups to try reaching 100 ps CTR and even 10 ps CTR, which translates into close to millimetric precision in the localization of emission points in the patient.

In this seminar, I will present an overview of the different aspects studied at Université de Sherbrooke in Canada in the past few years to predict and optimize the performance of (TOF-)PET detectors. First, peculiarities of the light collection in scintillators will be discussed. Then, I will highlight the strong connection between the interaction position in detectors and the CTR. Although this connection is at first detrimental since position-dependent time biases arise and limit the CTR performance, exploiting position-dependent features contained in signals can help correct these biases. It can be further shown that the current steady improvements in TOF-PET detector technologies bring out even sharper features exploitable to further push the CTR performance for TOF-PET imaging with unprecedented sensitivity.

Finally, I will present an overview of the recent endeavours in Sherbrooke in the development of a novel brain PET scanner with high spatial resolution for the neuroimaging of early processes implica- ted in neurodegenerative diseases.