title: Quantitative x-ray phase-contrast imaging using a single grating of comparable pitch to sample feature size.
abstract: The ability to quantitatively retrieve transverse phase maps during imaging by using coherent x rays often requires a precise grating or analyzer-crystal-based setup. Imaging of live animals presents further challenges when these methods require multiple exposures for image reconstruction. We present a simple method of single-exposure, single-grating quantitative phase contrast for a regime in which the grating period is much greater than the effective pixel size. A grating is used to create a high-visibility reference pattern incident on the sample, which is distorted according to the complex refractive index and thickness of the sample. The resolution, along a line parallel to the grating, is not restricted by the grating spacing, and the detector resolution becomes the primary determinant of the spatial resolution. We present a method of analysis that maps the displacement of interrogation windows in order to retrieve a quantitative phase map. Application of this analysis to the imaging of known phantoms shows excellent correspondence.
authors.affiliation: School of Physics, Monash University, Clayton, Victoria, Australia, 3800. kaye.morgan@monash.edu
authors.forename: Kaye S
authors.initials: KS
authors.lastname: Morgan
authors.forename: David M
authors.initials: DM
authors.lastname: Paganin
authors.forename: Karen K W
authors.initials: KK
authors.lastname: Siu
mesh_terms: D007091:Image Processing, Computer-Assisted; D055096:Optical Devices; D014965:X-Rays