With the advent of fast scintillator detectors with lutetium oxyorthosilicate (LSO) crystals, true time of flight (TOF) became a realistic innovation for the clinical setting.
Intensified research since the 2000s focusing on true TOF PET/CT systems has shown numerous advantages that LSO-based TOF brings, such as better definition of small lesions, improved uniformity, reduced noise, and sensitivity gain.