Design and simulation of a helmet brain PET system

Abstract

The desire to obtain a reconstruction image with high resolution using a short scanning duration motivates us to design a new brain positron emission tomography (PET) system. We design and simulate a wearable helmet brain PET system. This helmet PET scanner has a radius of 185 mm and comprises five parts (bottom, face, forehead, head, and top). The entire helmet PET system has 512 Lu1.8Y0.2SiO5: Ce (LYSO) PET detector blocks. Each PET detector is made of 12 × 12 LYSO crystals with 1.5 × 1.5 × 10 mm3elements. The proposed scanner has a global absolute sensitivity of 3.08% and a global scatter fraction of 0.56. Maximum likelihood expectation maximization (MLEM) reconstruction of the simulated data shows that full width at half maximum (FWHM) is 1.97 mm and full width at tenth maximum (FWTM) is 2.80 mm at the center of the field of view. In the radial direction, the FWHM increases from 1.97 mm to 3.82 mm, and the FWTM increases from 2.80 mm to 5.64 mm. In the axial direction, FWHM and FWTM are 1.98 mm and 2.80 mm, respectively. We use simulated line sources, a Derenzo phantom, and an MRI image to test the imaging ability of the simulated brain helmet PET. The scanner achieves higher resolution and higher sensitivity than a clinical PET scanner and will be of practical use in the diagnosis of brain illness.