Development of a Preclinical PET/MRI DOI Detector Using Different Types of Scintillators for Operation in a Magnetic Field

다국어 초록 (Multilingual Abstract)

We developed a high-resolution, preclinical positron emission tomography/magnetic resonance imaging (PET/ MRI) detector for measuring depth of interaction (DOI) without signal distortion in a magnetic field. A silicon photomultiplier (SiPM), a semiconductor photosensor, was used to operate in a high magnetic field, and a twolayer scintillator block was fabricated for DOI. The scintillator block used lutetium-yttrium oxyorthosilicate (LYSO) and gadolinium aluminum gallium garnet (GAGG) scintillators, so that the signal sizes acquired form each scintillator layer were different. After constructing the detector, a Na-22 radiation source was used to acquire flood images and energy spectra through gamma-ray interaction. By using different scintillators in each layer, the energy spectrum formed two photoelectric peak areas. Since the signal sizes differ depending on the characteristics of different scintillators, it is possible to determine the DOI layer when data is acquired by separating the photoelectric peak areas. If this detector is used as a DOI detector for preclinical PET/MRI, it will be possible to develop a system with excellent spatial resolution that can operate in a magnetic field.