3D and 4D imaging from multi-threaded cone-beam CT scans

Multi-threaded CT scanners with up to 3 X-ray tubes and corresponding detectors may have manifold applications. Previously we studied the application to phase-correlated imaging (e.g. cardiac CT) and performed simulations to investigate the optimal alignment of the tubes in order to achieve the best possible temporal resolution. In this paper, we describe the generalization of our Feldkamp-type "extended parallel backprojection" algorithm to cope with G threads. With this new version of the EPBP reconstruction algorithm, we performed 3D and 4D simulation studies on mathematical phantoms. The simulations clearly show a reduction of cone-beam artifacts for multi-slice spiral scans and approve the expected improvement in temporal resolution for phase-correlated imaging compared to a conventional single-threaded scanner.