Fig. 1

PET and MRI data are acquired simultaneously. The 2D iNAV is only available for part of the complete examination (i.e. during the CMRA acquisition). The feet-head (FH) motion signal is derived from the iNAV to generate the iNAV respiratory signal. The different colors (green, black, red, and cyan) each represent the bin in which the data acquired during this time window will be allocated. The breathing signal from the respiratory belt (thoracic motion) is available for the entire duration of the scan. By co-registration of the iNAV and belt respiratory signal in the period in which they are acquired simultaneously, the respiratory signal in the entire time period can be used to bin the PET data of the entire PET examination. The µ-map is deformed using the inverse motions fields to match the position of each bin. The deformed µ-map is used to reconstruct PET data for each bin. Next, these PET images are transformed to the end-expiration position using the motion fields again and combined to create the final motion-corrected PET image