Katsevich algorithm for spiral cone beam tomography with half-cover scan

Half-cover scan means x-ray beam horizontally covers half of the inspected object at each view angle. It can enlarge the field of view (FOV) of spiral cone-beam CT (computed tomography). In imaging algorithms of CT, Katsevich algorithm is exact and efficient. The imaging result is not influenced by cone-angle. If Katsevich algorithm used directly in spiral cone-beam CT, PI line is not completely covered by x-ray beam at each view. The image reconstructed by Katsevich algorithm based on PI line is partly absent. In this paper, an improved Katsevich algorithm is proposed for transversely truncated projection of half-cover scan. It canobtain complete reconstruction images with proposed algorithm. Numerical result validates the non-PI line imaging algorithm.