Dual-energy subtraction imaging (DES) is a method to improve the detectability of contrast agents over a lumpy
background. Two images, acquired at x-ray energies above and below an absorption edge of the agent material,
are logarithmically subtracted, resulting in suppression of the signal from the tissue background and a relative
enhancement of the signal from the agent. Although promising, DES is still not widely used in clinical practice.
One reason may be the need for two distinctly separated x-ray spectra that are still close to the absorption edge,
realized through dual exposures which may introduce motion unsharpness.
In this study, electronic spectrum-splitting with a silicon-strip detector is theoretically and experimentally
investigated for a mammography model with iodinated contrast agent. Comparisons are made to absorption
imaging and a near-ideal detector using a signal-to-noise ratio that includes both statistical and structural noise.
Similar to previous studies, heavy absorption filtration was needed to narrow the spectra at the expense of a
large reduction in x-ray flux. Therefore, potential improvements using a chromatic multi-prism x-ray lens (MPL)
for filtering were evaluated theoretically. The MPL offers a narrow tunable spectrum, and we show that the
image quality can be improved compared to conventional filtering methods.