A Novel CT Geometry

A conventional state-of-the-art CT detector forms an arc concentric to the x-ray source. For the cone-beam to parallel-beam conversion prior to the reconstruction, both channel- and view-wise rebinning are required, which leads to a compromised spatial resolution and elevated aliasing artifact. We present a novel detector geometry that enables the acquisition of projections with an evenly spaced distance to the isocenter. To ensure that the detector has a uniform cell size, the source-to-detector distance becomes a function of the detector fan-angle. The channel-wise rebinning to form a parallel dataset is therefore eliminated. Extensive computer simulations were used to verify our design. The proposed design offers a 12.6% increase in spatial resolution, resulting from a reduced detector cell size and the removal of the channel-wise interpolation. In addition, aliasing artifact is significantly reduced at locations away from the isocenter. At matched spatial resolution, image noise for the proposed system is 8.8% lower. Further research on this design is warranted to fully explore important systems parameters such as the compactness of the gantry design.