Among other things, one or more systems and/or techniques are described for dynamically adjusting, in a fan-angle direction, attenuation of radiation during an examination of an object such that portions of the object that are not represented in resulting (tilted/targeted) images of the object are exposed to less radiation than portions of the object that are represented in resulting (tilted/targeted) images of the object. As a rotating gantry is rotated, blades of a pre-object collimator are dynamically repositioned to selectively attenuate emitted radiation. A collimator adjustment component may be configured to determine how to reposition the blades based at least in part upon at least one of a desired tilt of the resulting (tilted) image(s), a translational position of the object, and a gantry rotation angle, for example.
