Image Quality assessment for Awake Animal Brain PET

A restrictive issue for small-animal positron emission tomography (PET) imaging is the fact that animals have to be either anaesthetized or physically restrained to prevent them from moving during the imaging procedure. Tracking the motion of the animal, based on e.g. radioactive point sources which are attached to the head of the animal, allows to scan awake animals. The use of radioactive point sources for motion tracking has the benefit that it can be used in scanners with small bore size or occluded views, is minimally invasive and does not require additional precise calibration between the PET camera and an external tracking device. The aim of this study was to assess the image quality and quantitative accuracy for PET scans of moving objects, with motion correction based on radioactive point sources, following the procedures of the NEMA NU 4-2008 standard. We found that even extensive motion of an object, including rotation and turning front to back, affects image quality as well as quantitation only marginally compared to the motion free scan.