HIGH-RESOLUTION COMPUTED TOMOGRAPHY

摘要

An x-ray imaging system (10), such as a X-ray computerised tomographic system, may acquire a series of radiographs at different detector positions along a first translation axis or a second translation axis parallel to orientation directions of detector pixels of a radiation detector (14). In a first embodiment, the different detector positions may be separated by a distance less than a linear size of the radiation detector (14) along the first translation axis or the second translation axis, respectively. The radiographs may be assembled into a radiograph larger than each radiograph in the series of radiographs, resulting in image stitching. In a second embodiment, the different detector positions may be separated by a distance less than a pixel size of the radiation detector (14), also referred as sub-pixel shifting of the detector. The radiographs may be assembled to form a radiograph with a higher resolution than the acquired radiographs, resulting in superresolution.

主权项

1. An x-ray imaging system comprising:
an x-ray generator configured to emit an x-ray beam; a two-dimensional pixelated area radiation detector having a plane arranged perpendicular to an emission direction of the x-ray beam, wherein a first translation stage and a second translation stage carry the radiation detector, wherein the first and second translation stages are configured to move the radiation detector along translation axes parallel to orientation directions of detector pixels of the radiation detector; and a rotation stage having a rotation axis perpendicular to the emission direction of the x-ray beam, wherein the rotation stage is disposed between the x-ray generator and the radiation detector, wherein the rotation stage is configured to carry and rotate a sample; a linear stage configured to translate the sample linearly along an axis parallel to the rotation axis of the rotation stage, wherein a motion of the rotation stage and a motion of the linear stage are synchronized such that the x-ray beam traces a spiral pattern on the sample; and an image acquisition system configured to:
acquire, while the radiation detector is at a first detector position, a first series of radiographs at a plurality of rotation angles of the rotation stage and a plurality of linear stage positions of the linear stage;after acquiring the first series of radiographs, acquire, while the radiation detector is at a second detector position, a second series of radiographs at the plurality of rotation angles and the plurality of linear stage positions, the second detector position being separated from the first detector position along either or both the translation axes by a distance less than a pixel size of the radiation detector;generate, based on radiographs in the first series of radiographs and corresponding radiographs in the second series of radiographs, a set of higher-resolution radiographs, wherein the higher-resolution radiographs have higher resolution than the radiographs in the first and second series of radiographs; andassemble the higher-resolution radiographs into a 3-dimensional radiograph of the sample.