1. A diagnostic imaging system which corrects metal artifact streaks emanating from a high attenuating object in an uncorrected tomographic image, the system comprising: a first vector means for determining a direction vector for each pixel, which direction vector points in the direction of the high attenuating object; a second vector means for determining an orientation vector for each pixel, which orientation vector coincides with a steepest gradient direction; and an adaptive filter means for adaptively filtering the uncorrected tomographic image based at least on the determined orientation of the steepest gradient vector.