Development of a Preclinical PET Scanner With DOI Capabilities Using Semi-Monolithic Detectors
[EN] Most preclinical PET scanners are based on pixelated detectors without Depth of Interaction (DOI) capabilities, which is crucial to correct for parallax errors. Semi-monolithic crystals have the potential to combine the timing capabilities of pixelated crystals and the 3D positioning accuracy o...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:dnet:riunet______::b97b5a01719a83a1220b71a62a067111 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/235768 |
| Access Level: | acceso abierto |
| Palabra clave: | Depth of interaction Preclinical PET Semimonolithic scintillator crystals SiPMs |
| Sumario: | [EN] Most preclinical PET scanners are based on pixelated detectors without Depth of Interaction (DOI) capabilities, which is crucial to correct for parallax errors. Semi-monolithic crystals have the potential to combine the timing capabilities of pixelated crystals and the 3D positioning accuracy of monolithic scintillators. In this work, we present a preclinical PET prototype consisting of 2 rings defining an inner diameter of 106 mm and an axial length of 52 mm. Each ring contains 14 arrays of 1 × 22 LYSO slabs of 0.97 mm × 25.6 mm × 12 mm, coupled to 8 × 8 SiPMs arrays. The sensitivity, spatial resolution, count rate performance and image quality were studied using the NEMA NU 4-2008 protocol. All images were reconstructed using the MLEM algorithm with 0.5 mm voxel size, including DOI information and normalization correction. A mean spatial resolution for all measured positions and across the three directions (axial, transaxial and radial) of 1.61 ± 0.19 mm was obtained at the center of the FOV. A peak sensitivity of 3.5% was obtained at the center of the scanner, for an energy window (EW) between 358 keV -664 keV. The noise equivalent count rate peak reached 106.9 kcps for an activity of 11.7 MBq using the mouse-sized phantom, the same EW window and a time coincidence window of 10 ns. For the image quality phantom, contrast recovery coefficients of 0.20, 0.62, 0.75, 0.81 and 0.85 were found for the 1, 2, 3, 4 and 5 mm rods, respectively. Spill-over-ratio values of 0.10 for air-filled and 0.23 for water-filled cylinders were measured. Also, according to the Rayleigh criterion, 1.5, 1.2 and 1 mm hot spots of a micro-Derenzo phantom were well distinguished. |
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