Patent ID: 7643611

Claim:
A radiography system, comprising: at least one penetrating radiation source for providing a penetrating radiation field; at least one partially transmissive radiation detector, wherein said partially transmissive radiation detector is interposed between an object region to be interrogated and the at least one penetrating radiation source, wherein the at least one partially transmissive radiation detector transmits a portion of the penetrating radiation field incident on the at least one partially transmissive radiation detector, and a shadow aperture comprising a plurality of radiation attenuating regions having at least one illumination aperture therebetween two or more of the plurality of radiation attenuating regions, wherein the shadow aperture is disposed between the at least one penetrating radiation source and the at least one partially transmissive detector, wherein the at least one illumination aperture allows the penetrating radiation field to reach the object region, wherein backscattered radiation from the object region is detected by the at least one partially transmissive radiation detector in shadowed regions of the at least one partially transmissive radiation detector that are shadowed by the radiation attenuating regions of the shadow aperture.