Enhanced spectral x-ray imaging

An apparatus for x-ray imaging comprising an x-ray source and an x-ray detector having a number of detector elements, wherein the x-ray source and the x-ray detector are arranged on a support that is able to rotate around a subject or object to be imaged to enable a set of projections at different view angles,

• wherein the apparatus is configured to operate the x-ray source in switched kVp mode for alternately applying at least two different voltages, including a lower voltage and a higher voltage, during rotation to enable lower-energy and higher-energy exposures over the set of projections, thereby providing for lower-energy projections and higher-energy projections,
• wherein the x-ray detector is a photon-counting multi-bin detector configured to allocate photon counts to multiple energy bins, and the apparatus is configured to select counts from at least a subset of the energy bins to provide corresponding photon count information for both lower-energy projections and higher-energy projections,
• wherein the apparatus is configured to perform material basis decomposition for each of a number of the lower-energy projections and higher-energy projections and/or for each of a number of combinations of at least one lower-energy projection and at least one higher-energy projection, based on the corresponding photon count information.