REDUCTION OF IMAGE ARTIFACTS FROM SUPPORT STRUCTURES IN TOMOGRAPHIC IMAGING

An apparatus for reducing image artifacts caused by over-ranging or clipping of the data collected in a tomographic scan using a patient support, models the density profile of the patient support with a polynomial. Coefficients of the polynomial are stored in a look-up table according to gantry angle and used to estimate the over-range data. The estimated data is blended with the in-range data by convolving an over-range mask indicating which data is in-range and which data is over-range with a box car convolution kernel which produces a trapezoidal weighting mask. This weighting mask is multiplied by the estimated data and then summed to the in-range data to correct for the over-range portions of the data collected.