It is possible to improve on the low skirt selectivity of the slice sensitivity profile (SSP) in spiral CT by interpolation of the raw data or suitable image after-processing. We determined the SSP function of spiral CT by means of a plexiglas phantom which we subsequently modified empirically-mathematically by a correction function until we obtained maximum possible skirt selectivity and smallest possible FWHM (= full width at half maximum) of the corrected image data set. The corrected image data set was obtained by bilateral convolution of a real image data set with a correction function. This resulted in most cases in a more realistic imaging of the angiographic morphology when applied to SSD and MIP (3D) reconstructions of a. mesenterica sup. and tr. coeliacus from spiral CT data sets, compared with the original data sets.