A CT scanner comprising a stator and a rotor having an axis of rotation mounted to the stator so that the rotor is rotatable about the axis of rotation comprising: an X-ray source mounted to the rotor, said X-ray source having a focal spot from which X-rays emanate; an X-ray detector array comprising a matrix of rows and columns of X-ray detectors; anti-scattering (AS) material for absorbing X-rays positioned between columns of the X-ray detectors; and anti-scattering (AS) material for absorbing X-rays positioned between rows of the X-ray detectors, whereby the AS material is located between every other row and/or column of detectors, respectively. Furthermore, the thickness and/or height of the foils between rows may be different from the thickness and/or height of the foils between columns.