Asymmetric-filter cone-beam dual-energy computed tomography

We previously proposed an implementation method for dual-energy computed tomography (DECT) with an asymmetrical absorption filter (AF) using fan-beam geometry, which we called the asymmetric filter method (AFM). The advantage of this method is its simple implementation since only the absorption filters need to be replaced for multiple implementations. Furthermore, this method performs the measurement required by DECT in a one-time scan. Recently, cone-beam CT has become relatively widespread for high-speed measurements as it has a measuring range wider than that of the fan-beam CT. In this study, we develop a method that is an extended version of the AFM for cone-beam CT. We employ an iterative reconstruction method and evaluate the proposed method numerically. The results show that the proposed method can accurately perform DECT reconstruction. Moreover, the proposed pixel size relaxation method recovers errors in the filter installation position.