Apparatus and method for radiation attenuation

摘要

An off-focal radiation collimator is disclosed which includes a plurality of radiation absorbing elements supported in spaced relationship with respect to one another in a housing such that each element is aligned along radii extending from the focal spot of a radiation source. The off-focal collimator is preferably disposed between the radiation source and a primary beam collimator. The off-focal collimator also acts as a radiation beam compensator. By varying the spatial density of the radiation absorbing elements by a function of location within the housing, the radiation beam can be shaped to any desired profile.