Phase-contrast imaging is performed by directing radiation from a plurality of pinhole sources through a phase object to be imaged, wherein the phase object includes a first composition that produces a phase shift in the radiation relative to radiation passing through a second composition in the phase object and detecting a phase-contrast image of the radiation after it passes through the phase object. The phase-contrast image is then decoded to generate an image of the phase object in which the first composition is distinguished from the second composition.