Certain embodiments of the present invention provide a method for x-ray imaging including: exposing a volume of interest to a first technique level to obtain a first set of image data; exposing the volume of interest to a second technique level to obtain a second set of image data; and estimating whether the volume of interest includes a foreign object based at least in part on a comparison of at least an aspect of the first set of image data and at least an aspect of the second set of image data. According to an embodiment, one of the first and second technique levels is selected to generate x-rays having a higher average energy than the other of the first and second technique levels. According to an embodiment, at least one of the first and second technique levels is selectable to cause an overexposure. According to an embodiment, at least one of the first and second technique levels corresponds to a clinical technique level.