One example method for estimating scatter associated with a target object may include acquiring a set of original projection data that includes primary radiation and scattered radiation at one or more selected projection angles associated with the target object, generating a first set of estimated scatter data from the set of original projection data, generating reconstructed image data by performing a first pass reconstruction using the first set of estimated scatter data, and generating a set of reference scatter data associated with the target based on the reconstructed image data. The example method may also include generating a set of reference primary plus scatter data associated with the target object based on the reconstructed image data, generating a second set of estimated scatter data associated with the target object based on the set of reference primary plus scatter data, and generating perturbation data associated with the target object.