Sparse background measurement and correction for improving imaging
Inventors
Bai, Chuanyong • Zahn, Robert • Gagnon, Daniel • Jain, Amit • YU, Zhicong • PREKAS, Georgios
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-11854123-B2
Publication Date
2023-12-26
Expiration Date
Abstract
Disclosed herein is an imaging system including a first x-ray source configured to produce first x-ray photons in a first energy range suitable for imaging, project the first x-ray photons onto an area designated for imaging, a rotatable gantry configured to rotate the first x-ray source such that the first x-ray source traverses an angular path, and a data processor having an analytical portion. The analytical portion is configured to collect first data relating to the transmission of the first x-ray photons through the area designated for imaging at a set of image-collection angles along the angular path, collect background data at a set of background-collection angles along the angular path, wherein the system acquires more than one image of the designated area for imaging between background angles. The analytical portion is also configured to remove errors in the first data using the background data, and generate a corrected image based on the removal of errors in the first data.
Core Innovation
The disclosure describes an imaging system that uses a first x-ray source and a rotatable gantry configured to rotate the first x-ray source such that the first x-ray source traverses an angular path. The system produces first x-ray photons in a first energy range suitable for imaging and projects them onto an area designated for imaging, while a data processor collects first data relating to transmission of the first x-ray photons through the designated area at a set of image-collection angles along the angular path.
In addition to image-collection data, the system collects background data at a set of background-collection angles along the same angular path and acquires more than one image of the designated area for imaging between background angles. The data processor removes errors in the first data using the background data and generates a corrected image based on the removal of errors in the first data.
The disclosure further describes sparse background x-ray detector measurements taken at selected gantry angles to correct image errors, including lag/ghosting and related residual effects observed in subsequent x-ray acquisitions. The described variations include selecting background-collection angles to maximize image acquisition between backgrounds, using minimum background measurement constraints, generating an error image based on interpolation of background data, and calibrating a detector time-decay response using the background data.
The disclosure also describes applying the approach during helical/multi-rotation CBCT reconstruction along a helical trajectory, including synchronized acquisition and reconstruction algorithm modification to handle non-uniform background sampling and staggered background measurements across rotations. Background measurements are interleaved across rotations and used as input for error imaging and correction in the reconstruction workflow.
Claims Coverage
The provided set includes three independent claims: clm-00001, clm-00032, clm-00037 (method), and an additional independent system claim clm-00038. Across these independent claims, the core inventive concept centers on acquiring transmission image data across image-collection angles and acquiring background data at background-collection angles along the same angular path, then removing errors using the background data to generate a corrected image, with clm-00032 specifically requiring interpolation using background data at two bounding angles.
Angular-path transmission with background-angle error removal
collect first data relating to transmission of the first x-ray photons through the area designated for imaging at a set of image-collection angles along the angular path; collect background data at a set of background-collection angles along the angular path, wherein the system acquires more than one image of the designated area for imaging between background angles; remove errors in the first data using the background data; and generate a corrected image based on the removal of errors in the first data.
Two-angle background interpolation for corrected image
collect background data at a first angle along the angular path; collect image data relating to transmission of the x-ray photons through the area designated for imaging over a range of angles along the angular path; collect background data at a second angle along the angular path, the second angle positioned such that the range of angles is between the first and second angles; generate a corrected image by removing errors in the image data using an interpolation of the background data collected at the first and second angles.
More-than-one-image acquisition between background angles
producing first x-ray photons in a first energy range suitable for imaging; projecting the first x-ray photons onto an area designated for imaging; rotating the first x-ray source such that the first x-ray source traverses an angular path; collecting first data relating to transmission of the first x-ray photons through the area designated for imaging at a set of image-collection angles along the angular path; collecting background data at a set of background-collection angles along the angular path, wherein the system acquires more than one image of the designated area for imaging between background angles; removing errors in the first data using the background data; and generating a corrected image based on the removal of errors in the first data.
Single background-angle correction
collect first data relating to transmission of the first x-ray photons through the area designated for imaging at a set of image-collection angles along the angular path; collect background data at a background-collection angle along the angular path; remove errors in the first data using the background data; and generate a corrected image based on the removal of errors in the first data.
Across the independent claims, the patent coverage is directed to an imaging system and method that acquire transmission image data at multiple image-collection angles along an angular path and acquire background data at background-collection angles along the same angular path. The data processor removes errors in the transmission data using the background data and generates a corrected image, with clm-00032 additionally requiring interpolation between background data at first and second angles that bound the range of image angles.
Stated Advantages
Correcting errors in image data by removing errors using background data and generating a corrected image.
Using background data acquired between background angles, with the system acquiring more than one image between background angles.
Generating a corrected image by removing errors using an interpolation of background data collected at first and second angles.
Documented Applications
Background-based error correction in subsequent x-ray acquisitions, including correction of image errors such as lag/ghosting and related residual effects.
Use during helical/multi-rotation CBCT reconstruction along a helical trajectory.
Interested in licensing this patent?