An apparatus and method for obtaining a thick-slice image from tilted thin-slice computed-tomography (CT) projection data. Tilted CT projection data is obtained for a series of projection planes, wherein the projection planes are parallel for all scans, and the translation direction between CT scans is not orthogonal to the projection planes (i.e., the projection planes are tilted relative to the translation direction between CT scans). Thin-slice images are reconstructed from the respective CT scans, and then grouped into thick-slice groupings. An offset results among the thin-slice images within a thick-slice grouping due to the tilt of the projection planes. This offset is compensated by interpolating and resampling the thin-slice images onto non-offset pixel grids. The interpolated and resampled thin-slice images are then averaged pixel-by-pixel to obtain thick-slice images having the same tilt angle as the thin-slice images.
