| 摘要 |
<p>An off-focal radiation (40) collimator which includes a plurality of radiation absorbing elements (41) supported in spaced relationship with respect to one another in a housing (43) such that each element is aligned along radii extending from the focal spot (25) of a radiation source. The off-focal collimator is preferably disposed between the radiation source and a primary beam collimator (24). The off-focal collimator also acts as a radiation beam compensator. By varying the spatial density of the radiation absorbing elements (41) by a function of location within the housing, the radiation beam can be shaped to any desired profile.</p> |
