Methods for saturation correction and dynamic gain configuration and apparatuses for performing the same
Inventors
YU, Zhicong • Jain, Amit • Gagnon, Daniel • Bai, Chuanyong • Chappo, Marc
Assignees
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Publication Number
US-12257083-B2
Publication Date
2025-03-25
Expiration Date
Abstract
Saturation in at least one saturated ray is in a method including identifying a saturated ray corresponding to a first ray of a radiation source received at a radiation detector after passing through a reference point during a current view of the radiation detector, identifying at least one non-saturated ray corresponding to a second ray of the radiation source received at the radiation detector, and responsive to the identifying, adjusting a value for the saturated ray based on a value of the at least one non-saturated ray. The non-saturated ray can be a ray from an adjacent view of a current rotation, an adjacent view of a previous or subsequent rotation, or a conjugate ray. Methods of selecting a gain level to avoid saturation are also disclosed.
Core Innovation
The disclosed subject matter provides a dual-energy computed tomography approach that corrects saturation in at least one saturated ray detected after the ray passes through a reference point during a current view and saturates a pixel of a radiation detector. In this approach, a saturated ray corresponding to a first ray of a radiation source is identified for the current view, while one or more non-saturated rays corresponding to rays of the radiation source are identified for other views. The correction is performed by adjusting a value for the saturated ray responsively based on the value of the non-saturated ray(s).
The correction is grounded in using non-saturated projection information from adjacent views with different radiation source energies. The method identifies at least one non-saturated ray corresponding to a second ray of the radiation source during a previous view and/or a third ray during a next view, where the previous view and the next view are adjacent to the current view and have a first energy for the current view and a second energy different from the first energy for the previous and next views. Based on the identification, the method adjusts the saturated-ray value using the non-saturated-ray value(s).
A related correction approach is provided for using conjugate views, where a non-saturated ray is identified in a conjugate view adjacent to a third ray that is rotated 180° with respect to the first ray. In both the adjacent-view and conjugate-view settings, the saturation correction is achieved by adjusting the value for the saturated ray based on the value of the at least one non-saturated ray, supported by the disclosed dual-energy CT context and the associated radiation source, radiation detector, controller, and views (current, previous, next, and conjugate).
Claims Coverage
Two independent methods are identified. Both methods focus on the same inventive core: identify a saturated ray in a current view and adjust its value based on one or more non-saturated rays from other views, with additional constraints on how the other rays relate to adjacent views and energies or to conjugate 180° rotation.
Adjacent-view non-saturated-ray saturation correction with differing energies
identifying a saturated ray corresponding to a first ray of a radiation source received at a radiation detector after passing through a reference point during a current view of the radiation detector and saturates a pixel; identifying at least one non-saturated ray corresponding to a second ray during a previous view and/or a third ray during a next view where the previous view and the next view are adjacent to the current view and the radiation source has a first energy for the current view and a second energy different than the first energy for the previous view and the next view; responsive to the identifying, adjusting a value for the saturated ray based on a value of the at least one non-saturated ray.
Conjugate-view adjacent non-saturated-ray saturation correction with 180° rotated ray
identifying a saturated ray corresponding to a first ray received at the radiation detector after passing through a reference point during a current view and saturates a pixel; identifying at least one non-saturated ray corresponding to a second ray after passing through the reference point during a conjugate view and not saturating a pixel, wherein the second ray is adjacent to a third ray that is rotated 180° with respect to the first ray; responsive to the identifying, adjusting a value for the saturated ray based on a value of the at least one non-saturated ray.
Across both independent claims, saturation is corrected by adjusting the saturated-ray value using non-saturated rays. One independent claim anchors the correction to previous/next adjacent views with different radiation source energies, and the other anchors it to a conjugate view with an adjacent ray relationship that includes a 180° rotated ray.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
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