Contrast enhancement for CT systems

The present invention, in one form, is a method for improving grey-white matter differentiation between regions of an image to be reconstructed from data obtained by a CT scan. More particularly, in accordance with one form of the present invention, a re-mapping function is utilized to generate CT numbers. In accordance with such function, CT numbers that are outside the grey-white matter region are not "stretched". The CT numbers within such region are "stretched" with the larger "stretch" centered on the grey-white matter region and tapering off at the boundary. Using such a function, grey-white matter differentiation is improved without adversely affecting quality and accuracy.