1. A statistical iterative image reconstruction method for use in computed tomography (CT), the method comprising: generating an image; generating a set of calculated measurements based on the image; generating a set of actual measurements derived from a set of CT image data; determining whether a completion criterion is satisfied; if the completion criterion is satisfied, providing the image as a final image; if the completion criterion is not satisfied, generating an image update of the image, applying a deconvolution filter or a square root of the deconvolution filter to one or both of the image or the image update, and repeating the steps of generating the set of calculated measurements and determining whether the completion criterion is satisfied.