Patent ID: 8194821

Claim:
A method of taking a radiographic projection of an object, the method comprising: disposing an object between a radiation source and an imaging device, with a spatial modulator being disposed between the radiation source and the object, the spatial modulator comprising a body of material, a plurality of first regions in the body that have thicknesses that are equal to or less than a first thickness value, and a plurality of second regions in the body that have thicknesses that are greater than the first thickness value, wherein a plurality of first regions are disposed along a geometry line with one or more of the second regions being disposed between said plurality of the first regions, wherein at least one of the first regions has transmission factor T 1 for radiation passing through the at least one of the first regions, wherein a second region adjacent to said at least one of the first regions has a second transmission factor T 2 for radiation passing through said second region, and wherein the ratio of the second transmission factor T 2 to the first transmission factor T 1 is in the range of 0.85 to 0.97; and exposing the object to radiation from the radiation source so that radiation passing through a plurality of first regions and a plurality of second regions of the spatial modulator strikes the object at the same time.