Phase-contrast and dark-field CT reconstruction algorithm

A signal processing method, comprising:

• receiving interferometric projection data derived from signals acquired by an X-ray detector of an interferometric X-ray imaging apparatus, said signals caused by X-ray radiation after interaction of said X-ray radiation with an interferometer and with an object to be imaged, said interferometer having an inter-grating distance;
• performing, based on the projection data and a forward signal model of a phase contrast signal, a reconstruction operation for one or more images in an image domain of a spatial distribution of at least one physical property of said object including a refractive index, wherein the reconstruction operation is an operation in a phase contrast signal channel with the refractive index as an observable, wherein the reconstruction operation includes performing a scaling operation based on the inter-grating distance of the interferometer and/or on a distance of a location in said image domain from said interferometer;
• and
• outputting said one or more images.

A non-transitory computer readable medium having one or more executable instructions, which, when executed by processor circuitry, cause the processor circuitry to perform a method comprising:

• receiving interferometric projection data derived from signals acquired by an X-ray detector of an interferometric X-ray imaging apparatus, said signals caused by X-ray radiation after interaction of said X-ray radiation with an interferometer and with an object to be imaged, said interferometer having an inter-grating distance;
• performing, based on the projection data and a forward signal model of a phase contrast signal, a reconstruction operation for one or more images in an image domain of a spatial distribution of at least one physical property of said object including a refractive index, wherein the reconstruction operation is an operation in a phase contrast signal channel with the refractive index as an observable, wherein the reconstruction operation includes performing a scaling operation based on the inter-grating distance of the interferometer and/or on a distance of a location in said image domain from said interferometer;
• and
• outputting said one or more images.