Optimization of GFAG crystal surface treatment for SiPM based TOF PET detector.
Han Gyu KangKyoung Jin KimKei KamadaAkira YoshikawaEiji YoshidaFumihiko NishikidoTaiga YamayaPublished in: Biomedical physics & engineering express (2022)
Coincidence timing resolution (CTR) is an important parameter in clinical positron emission tomography (PET) scanners to increase the signal-to-noise ratio of PET images by using time-of-flight (TOF) information. Lutetium (Lu) based scintillators are often used for TOF-PET systems. However, the self-radiation of Lu-based scintillators may influence the image quality for ultra-low activity PET imaging. Recently, a gadolinium fine aluminum gallate (Ce:GFAG) scintillation crystal that features a fast decay time (∼55 ns) and no self-radiation was developed. The present study aimed at optimizing the GFAG crystal surface treatment to enhance both CTR and energy resolution (ER). The TOF-PET detector consisted of a GFAG crystal (3.0 × 3.0 × 20 mm 3 ) and a SiPM with an effective area of 3.0 × 3.0 mm 2 . The timing and energy signals were extracted using a high-frequency SiPM readout circuit and then were digitized using a CAMAC DAQ system. The CTR and ER were evaluated with nine different crystal surface treatments such as partial saw-cut and chemical polishing and the 1-side saw-cut was the best choice among the treatments. The respective CTR and ER of 202 ± 2 ps and 9.5 ± 0.1% were obtained with the 1-side saw-cut; the other 5-side mechanically polished GFAG crystals had respective values which were 18 ps (9.0%) and 1.3% better than those of the all-side mechanically polished GFAG crystal. The chemically polished GFAG crystals also offered enhanced CTR and ER of about 17 ps (8.2%) and 2.1%, respectively, over the mechanically polished GFAG crystals.
Keyphrases
- positron emission tomography
- pet imaging
- computed tomography
- image quality
- mass spectrometry
- pet ct
- high frequency
- ms ms
- endoplasmic reticulum
- estrogen receptor
- room temperature
- transcranial magnetic stimulation
- solid state
- air pollution
- contrast enhanced
- optical coherence tomography
- dual energy
- magnetic resonance imaging
- healthcare
- high resolution
- single molecule
- deep learning
- radiation induced
- social media
- radiation therapy
- replacement therapy
- machine learning
- dengue virus