Simulation of a semiconductor voxelized helmet brain PET scanner

Abstract

Alzheimer's disease (AD) is a mental deterioration that severely impacts memory, disrupts brain functionality and induces physical changes to the brain. It is at present an incurable disease but a timely diagnosis of AD can help to slow down its progression. Invasive methods to collect cerebrospinal fluid (CSF) biomarkers are increasingly being used for the diagnosis of AD. Alternatively, because of the growing effort in trying to detect the early markers of AD, nowadays there are many neuroimaging projects developing non-invasive dedicated brain positron emission tomography (PET) scanners with a helmet shape. In this work, a helmet shaped brain PET is proposed with high spatial and energy resolutions, which could play a vital role in the early diagnosis of AD. It consists of highly 3D segmented detector modules with a density of more than 350 channels/cm3 and a seamless geometry based on trapezoidal-shaped modules equipped with semiconductor CdTe detectors. The proposed helmet brain PET scanner has an axial field-of-view (FOV) of 154 mm, and inner and outer radii of 133 mm and 206 mm respectively. Its performance has been evaluated via simulations based on NEMA protocols and compared to other brain PET scanners. Additionally, brain PET/CT images in DICOM format were used for a more realistic and stringent test of the imaging quality of the proposed PET scanner and the reconstruction of regional FDG uptakes. Results are presented that show that the proposed PET scanner can detect deviations in uptake of 2% or larger from a reference image.