Boundary-enhanced region-of-interest image reconstruction in propagation-based x-ray phase-contrast tomography

Propagation-based phase-contrast tomography is an imaging method that can reconstruct the distribution of the three-dimensional complex-valued refractive index distribution of an object. In many applications, a boundary-enhanced image is sought that reveals the locations of boundaries in the refractive index distribution. In this letter, we demonstrate that within certain regions-of-interest, the three-dimensional Laplacian of the real-valued component of the refractive index distribution can be reconstructed from knowledge of truncated phase-contrast projection data. The proposed reconstruction algorithm is demonstrated by use of experimental measurement data.