A filter assembly for CT system with multiple X-ray sources

There is a filter assembly (30) for a spectral filtering of the X-ray radiation of a CT system (1) described with a first (2) and a second x-ray source (4). The filter assembly (30) has an inner filter portion (31) which covers a cross sectional area of ​​a fan beam (13) of the first X-ray source (2) and an outer filter portion (32), which together with the inner filter region (31) has a greater covers a larger cross sectional area of ​​the fan beam (11) of the second X-ray source (4). Here, the inner filter region (31) to a first spectral filter function. Furthermore, the outer filter portion (32) in the z-direction into two portions (33, 34) is divided. In addition, the first portion (33) a second spectral filter function, and has the second portion (34) different from the second filter function third spectral filter function. It is also described a computed tomography system (1). In addition, a method (400) of manufacturing a filter assembly (30) for a spectral filtering of X-rays of a CT system (1) having a first X-ray source (2) and a second x-ray source (4) is presented. Moreover, a method (500) for reconstructing image data (BD