1. A method for reconstructing cardiac images using a computed tomographic (CT) imaging system, said method comprising the steps of: selecting a helical scanning pitch for scanning a patient; scanning the patient, including the patient's heart, with a computed tomographic imaging system having a plurality of detector rows and a rotating gantry to acquire projection data from the plurality of detector rows; selecting a phase of the cardiac cycle for imaging; combining portions of the acquired projection data from a plurality of detector rows, the combined portions corresponding to the selected cardiac phase; and reconstructing images, including images of the patient's heart, from the combined, interpolated projection data.