The present invention relates to an examination apparatus and a corresponding method to realize a Spectral x-ray imaging device through inverse-geometry CT. The proposed examination apparatus comprises: an X-ray source unit (14) comprising a plurality of X-ray sources (15) for emitting X-rays (24) at a plurality of locations, an X-ray detection unit (18) for detecting X-rays emitted from one or more of said X-ray sources (15) after penetration of an examination area (19) between said X-ray source unit (14) said X-ray detection unit (18) and for generating detection signals, a processing unit (36) for processing the generated detection signals, and - a control unit (26) for controlling said X-ray sources (15) to subsequently, alone or in groups emit X-rays at at least two different energy spectra such that in the time interval, during which a particular X-ray source (15a) or said group of X-ray sources (15a,15d, 15g), is switched over to emit X-rays at a different energy spectrum, said particular X-ray source (15a) or said group of X-ray sources (15a, 15d, 15g) is switched off and one or more other X-ray sources (15b, 15c) or groups of X-ray sources (15b, 15e, 15h 15c, 15f, 15i) are subsequently switched on to emit X-rays.Cette invention concerne un appareil dexamen et un procédé correspondant permettant dobtenir un dispositif dimagerie radiographique spectrale par tomodensitométrie à géométrie inverse. Lappareil dexamen de linvention comprend : une unité source de rayons X (14) comprenant plusieurs sources de rayons X (15) qui émettent des rayons X (24) en plusieurs endroits, une unité de détection des rayons X (18) qui détecte les rayons X émis par une ou plusieurs desdites sources de rayons X (15) une fois quils ont pénétré une zone à étudier (19) entre ladite unité source de rayons X (14) et ladite unité de détection des rayons X (18) et qui génère des signaux de détection, une unité de traitement (36) qui traite les signaux de détection générés, et une unité de
