Practical PET Normalization Methods using a Stationary Line Source

Crystal efficiency normalization is a critical component of the PET image generation chain for the generation of accurate and artifact-free images. Crystal efficiency normalization needs to be performed periodically and is typically performed using a cylinder phantom that covers most of the transaxial FOV and the entire axial FOV. The preparation of big, long and heavy phantoms is challenging, especially as the axial FOVs of PET scanners become increasingly longer to achieve higher sensitivity. One approach to overcome these difficulties is to use a rotating rod source, which effectively mimics a cylinder source with a line source. Such an approach is still somewhat complicated due to the need for a rotating rod. In this work, we propose two practical methods for crystal efficiency normalization using a stationary line source. In these methods, no phantom movement is required and the use of a simple line source is convenient in terms of preparation and storage.