Method for obtaining at least four radiographic projections and corresponding reconstruction device

A method (100) of obtaining at least four radiographic projections of an object in at least two different perspectives (s1 and s2), the at least four projections are used in a computed tomography (CT) measurement (e.g. for reconstructing volumetric properties at ray intersections from said at least two perspectives (s1 and s2). of the object), the method comprises the following steps: obtaining at least two first projections of the at least four projections from one first perspective which includes the ray attenuation belonging to a first path length through the object (e.g. approximating the longest path length, within a given set of rays and perspectives (s1 and s2) (CT geometry)), wherein the at least two first projections of the at least four projections from the one first perspective being recorded (e.g. from this perspective) using different energy spectra (which constitute the recorded intensities in congruent rays; note the first may the low-energy (LE) portion the second the high-energy (HE) portion of this perspective); obtaining at least two second projections of the at least four projections from at least one second perspective which includes the ray attenuation belonging to a second path length through the object (e.g. approximating the shortest path length) through the object (within a given set of rays/perspectives (s1 and s2)), wherein the at least two second projections of the at least four projections from the one second perspective being recorded (e.g. from this perspective) using different energy spectra (which constitute the recorded intensities in congruent rays; note one may be the LE portion the second the HE portion of this second perspective); and ray-wise weighting (130) and summing the at least two first projections and at least two second projections using a cost.