1. A method for reconstructing an image using an imaging apparatus comprising a radiation source, a detector array, and a computer, said method comprising: performing a helical scan of an object at a selected helical pitch using the radiation source and detector array to obtain image data; and reconstructing an image of the object utilizing the computer programmed to perform a hybrid cone beam image reconstruction having ray-wise 3D weighting, wherein the weighting is dependent upon both helical pitch and z-distance.