A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section with a length and thickness. A plurality of wedges is provided between the source and object. An actuator is connected to the wedges for moving the wedges substantially perpendicular to the length of the cross-section of the collimated x-ray beam. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of wedges. A gantry rotates the x-ray source, the plurality of wedges, and the x-ray detector around an axis of rotation.
