Single-exposure X-ray dark-field imaging method based on dual-detector grating interferometer

Abstract

The invention discloses a single exposure X-ray dark field imaging method based on a grating interferometer with double detectors. The grating interferometer with double detectors composed of an X-raysource, a phase grid, a first detector and a second detector is arranged. A working point of the first detector is fixed to the peak of a light intensity curve to acquire a background projecting image and an imaged object projecting image separately; a working point of the second detector is fixed to the valley of the light intensity curve to acquire a background projecting image and an imaged object projecting image separately; and a dark field signal of the imaged object is extracted by mean of the acquired image. According to the method, tedious grid stepping scanning is abandoned, so thatthe X-ray dark field imaging process is simplified; the imaged object is exposed primarily, so that the radiation damage risk is reduced; the problem of accurate extraction of a dark field signal inlow photon counting is solved, so that a new path is provided for developing a rapid, accurate and low radiation dosage X-ray dark field imaging technology.

Description

technical field [0001] The invention relates to the field of hard X-ray imaging physics and methods, in particular to a single-exposure X-ray dark-field imaging method based on a double-detector grating interferometer. Background technique [0002] As a powerful supplement to the traditional X-ray absorption contrast imaging technology, the X-ray dark-field imaging method has been developed rapidly in recent years. In particular, dark-field imaging based on a hard X-ray grating interferometer can detect internal features of objects whose spatial scale is lower than the resolution of the imaging system. It has a very broad application prospect in clinical medicine application fields. [0003] Existing hard X-ray grating interferometers generally use the phase stepping method to collect experimental data and extract object information. The phase step method requires: complex horizontal step scanning grating, resulting in a long data acquisition time, reducing the experimenta...

AI Technical Summary

Problems solved by technology

The phase step method requires: complex horizontal step scanning grating, resulting in a long data acquisition time, reducing the experimental efficiency; collecting multiple object projection images, at least four in the actual experiment, increasing the radiation dose and radiation damage of the object risk

More importantly, in the case of low photon counting, that is, low radiation dose, the phase stepping method cannot accurately extract the dark field signal of the object

These limitations hinder the popularization and application of X-ray grating interferometer in clinical medical diagnosis, in vivo imaging and other fields

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