Illustration of the MAD-based FFM concept: A) Simplified CT diagram where the MAD is placed in front of the x-ray source. B) On a fine scale the MAD filter selectively entirely blocks or entirely permits x-ray transmission, so that (in this example) there is more x-ray fluence at the center of the field than at the edge. C) With the use of two MAD filters one can create an entire class of modulation patterns using small relative motions between the MADs. In this case, two identical MAD filters create a fluence pattern identical to the single MAD scenario when perfectly aligned, and, when displaced, the fluence pattern exhibits a relative concentration of fluence in the center as compared with the edge detector elements.