An imaging system (500) includes a focal spot (510) that rotates along a path around an examination region (506) and emits radiation. A collimator (512) collimates the radiation, producing a radiation beam (516) that traverses a field of view (520) of the examination region and a subject or object therein. A detector array (522), located opposite the radiation source, across the examination region, detects radiation traversing the field of view and produces a signal indicative of the detected radiation. A beam shaper (524), located between the radiation source and the collimator, rotates in coordination with the focal spot and defines an intensity profile of the radiation beam. The beam shaper includes a plurality of elongate x-ray absorbing elements (606) arranged parallel to each other along a transverse direction with respect to a direction of the beam, separated from each other by a plurality of material free regions (604).
