An improved super-short-scan reconstruction for fan-beam computed tomography

We propose an improved super-short-scan reconstruction algorithm for fan-beam computed tomography based on pi-lines in this paper. Within the framework of the classic FBP algorithm, this new algorithm can achieve exact reconstruction of the region of interest (ROI), if and only if all lines passing through the ROI intersect the source trajectory. The new reconstruction formula successfully avoids the direct derivative of projection data and is expressed as the combination of Hilbert filter and Ramp filter rather than weighted Hilbert filter. This helps increase the numerical stability and improves the quality of reconstructed images, as the real data reconstruction involves discrete data. A preliminary computer simulation study has been done, and a comparison with other classic super-short-scan reconstruction algorithms proves the validation of this new algorithm.