Normalization factors for the ClearPET/spl trade/ Neuro

Inhomogeneities in the lines of response (LOR) sensitivity of a PET scanner are a source of artifacts in the reconstructed image. Appropriate normalization before reconstruction is therefore required to obtain artifact-free images. Differences in the LOR sensitivities are mainly due to different detector responses and geometric effects. The relative importance of the different normalization factors is affected by the individual scanner geometry and potential scanner rotation. We discuss relevant normalization factors for the ClearPETtrade Neuro, a recently developed small-animal PET scanner, and their importance with respect to the unconventional geometry of the scanner. It is shown that homogeneous images can be obtained, provided that all normalization procedures are performed properly