Abstract
Abstract
Small-animal PET, also known as microPET, has been developed
to enhance image quality by improving spatial resolution and
sensitivity due to its smaller ring and crystal size. However, the
reduction of crystal size and the presence of gaps between cuboidal
crystals could reduce sensitivity. MicroPET with tapered arrays has
been developed to simultaneously improve sensitivity and spatial
resolution. This study compared the performance of 14 × 14
and 28 × 28 array microPETs using LSO and CZT crystal
materials. The impact of crystal design and reconstruction
algorithms on image quality and performance parameters was
investigated, using GATE Monte Carlo simulation toolkit. The
findings showed that sensitivity increased with crystal thickness,
particularly in LSO. The 14 × 14 arrays consistently
exhibited higher sensitivity, while the 28 × 28 arrays had
superior spatial resolution. NECR values increased with crystal
thickness, with LSO outperforming CZT. Scatter and random fractions
were low. Different reconstruction algorithms had negligible effects
on FWHM and CNR but influenced SNR, with the COSEM algorithm
achieving significantly reduced noise. The small size of crystals
and tapered arrays contributed to improved sensitivity and spatial
resolution. However, there was a trade-off between sensitivity and
spatial resolution. LSO crystals showed better performance, but the
choice between array sizes depended on specific imaging
requirements. This study provides insights into optimizing microPET
design for enhanced imaging capabilities.