Progresses in designing a high-sensitivity dodecahedral PET for brain imaging

Dedicated brain PET has the potential to achieve better sensitivity, spatial resolution and image quality than conventional whole body PET cameras in brain tomography. Spherical PET (S-PET), that can achieve a higher geometrical sensitivity and a lower parallax error than conventional cylindrical ring PET scanners, is a good candidate for high performance dedicated brain imaging. Our simulation studies show that the S-PET has a local geometric efficiency 2.7 times higher than the 30cm cylinder PET, and 19 times higher than the 76cm cylinder PET in the zones around the cerebral cortex. However, it is very challenging to design detectors with curved surface for S-PET. Convex polyhedron PETs, such as dodecahedral PET, is easier to build and has the potential to achieve performances equivalent to those of S-PETs. We are building a high-sensitivity dodecahedron PET for brain imaging. In this paper, we report our progresses in: (1) sensitivity simulation studies, (2) design, simulation and fabrication of a pentagon-shaped detector module, (3) design and fabrication of the mechanic gantry, and (4) image reconstruction.