1. A CT system comprising: a gantry having a rotatable base and having an opening for receiving an object to be scanned; an x-ray source; a CT detector; and a computer programmed to: detect a mis-registration at a slab boundary between a first slab and a second slab of a reconstructed image; quantify an amount of mis-registration at the slab boundary; and adjust the reconstructed image at the slab boundary based on the quantification.