Helical CT Motion Compensation via Partial Angle Reconstruction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Helical computed tomography (CT) scans face significant challenges in motion artifact reduction due to patient movement during scans, which existing techniques fail to adequately address, especially given the changing field of view in helical scans.
Innovation Solution
A method and system for estimating and compensating for motion by selecting pairs of sections along the radiation source trajectory, performing image registration to estimate deformation, and generating a motion-compensated image using helical CT scan data, which involves reconstructing partial images from opposing sections and applying deformation to correct for object motion during the scan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional image reconstruction techniques are used for helical CT scans, then the scanning process is simple and fast, but motion artifacts appear in the reconstructed images due to patient movement during scanning
Solution Approach 1:
The patent divides the helical scan trajectory into multiple discrete sections and identifies corresponding pairs of sections. By processing each pair separately through image registration, the complex motion compensation problem is segmented into manageable units, reducing overall computational complexity while improving image quality
Solution Approach 2:
The patent performs image registration on pairs of sections from opposite sides of the trajectory before final image reconstruction. This preliminary estimation of deformation allows motion compensation to be applied during reconstruction, preventing motion artifacts rather than correcting them afterward
2Measurement precision
If the scan duration is extended to capture more data for better reconstruction, then image reconstruction quality improves, but patient motion during scanning increases causing more motion artifacts
Solution Approach 1:
The patent uses image registration to estimate deformation between sections and applies this feedback information during the reconstruction process. By continuously adjusting for estimated motion based on paired section comparisons, the system maintains high reconstruction accuracy without requiring extended scan times
Solution Approach 2:
The patent systematically processes pairs of sections at regular intervals along the helical trajectory. This periodic sampling and registration approach provides consistent motion estimation throughout the scan, maintaining reconstruction accuracy while keeping the overall scan duration reasonable
3Reliability
If motion compensation techniques are applied to helical CT scans, then motion artifacts are reduced, but the computational complexity and processing time increase significantly
Solution Approach 1:
The patent segments the motion compensation task into discrete pairs of sections, processing only corresponding pairs from opposite sides of the trajectory. This segmentation reduces the total number of registration operations required compared to processing all sections individually, decreasing processing time while maintaining image quality
Solution Approach 2:
The patent applies motion compensation selectively to specific pairs of sections rather than attempting to process the entire dataset uniformly. This partial action approach focuses computational resources on the most critical motion-corrected regions, reducing overall processing time while still achieving effective motion artifact reduction
Data Source
AI summary
An improved system and method for estimating and compensating for motion by reducing motion artifacts produced during image reconstruction from helical computed tomography (CT) scan data. In a particular embodiment, the reconstruction may be based on helical partial angle reconstruction (PAR).