1. An imaging system comprising: an x-ray source that emits a beam of x-rays toward an object to be imaged; a detector that receives the x-rays attenuated by the object; a spectral notch filter positioned between the x-ray source and the object; a data acquisition system (DAS) operably connected to the detector; and a computer operably connected to the DAS and programmed to: acquire a first image dataset at a first kVp; acquire a second image dataset at a second kVp that is greater than the first kVp; and generate an image of the object using the first image dataset and the second image dataset.