Field of view alignment on a multimodal PET/CT scanner for small animals

This work describes a procedure for the alignment of the fields of view of a multimodal system. Combined PET/CT systems for small-animal imaging usually have two axially displaced fields of view (FOV) that are mechanically aligned only to a certain degree; the remaining errors can impair sub- millimeter registrations. The correction of these residual uncertainties in the geometry is calculated using a software tool that automatically computes the misalignment between FOVs and compensates for them during image reconstruction. The procedure only requires the use of a simple phantom for calibration.