DetectorsforSmall-Animal PET

The adventof new all-digital electronic architectures inPETscanners enables thedevelopment and investigation ofnovelcrystal identification algorithms for phoswich detectors usedforparallax mitigation orhigher detector pixelisation. Thehighflexibility andrealtime signal processing capability ofFPGA/DSP-based digital electronics, suchastheonedeveloped fortheLabPETTM scanner, provide anexcellent platform totestenhanced digital methods. A novelapproach basedonthewavelet analysis theoryhas beeninvestigated forcrystal identification inphoswich detectors withcrystals having similar scintillation characteristics suchasLYSO (tr-40 ns)andLGSO (tr-65ns).Theproposed algorithm uses Stationary Wavelet Transform toclean thedigitized signal andDiscrete Wavelet Transform forcrystal identification. Suchaprocess canachieve asuccessful discrimination rate of- 95%forPETevents measured withanLYSO-LGSO phoswich crystal combination readoutbyanavalanche photodiode.