title: Stability of phase-contrast tomography.
abstract: Phase-contrast tomography (PCT) allows three-dimensional imaging of objects that display insufficient contrast for conventional absorption-based tomography. We prove that PCT is stable with respect to high-frequency noise in experimental phase-contrast data, unlike conventional tomography, which is known to be mildly unstable. We use known properties of the three-dimensional x-ray transform and transport-of-intensity equation to construct a matrix representation of the forward PCT operator. We then invert this formula to show that, under natural boundary conditions, the PCT reconstruction operator exists and leads to a unique solution. We show that the singular values s(n) of the reconstruction operator have asymptotic behavior s(n)=O(n(-3/2)), guaranteeing the mathematical stability of the reconstruction process.
authors.affiliation: Schoolof Physics, Monash University, Victoria, Australia. glenn.myers@sci.monash.edu.au
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Myers
authors.forename: Timur E
authors.initials: TE
authors.lastname: Gureyev
authors.forename: David M
authors.initials: DM
authors.lastname: Paganin