Constrained Backprojection for Undersampled MRI Reconstruction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MRI reconstruction methods require a large number of projection views to achieve adequate image quality, leading to lengthy scan times and potential artifacts due to insufficient sampling, especially in dynamic studies where subject changes occur.
Innovation Solution
A highly constrained backprojection method that utilizes a composite image with a priori knowledge of the signal contour in the field of view to weight signal distribution, allowing for significantly fewer projection views to be acquired while maintaining image quality, with the option to update composite images during dynamic studies to reflect changing subject conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large number of projection views are acquired to achieve adequate image quality, then image quality is improved, but scan time increases significantly
Solution Approach 1:
A composite image is reconstructed beforehand from all acquired projection views to provide a priori knowledge of the signal contour in the field of view. This preliminary composite image is then used to constrain and guide the backprojection reconstruction of individual image frames, allowing high-quality reconstruction with far fewer projection views per frame.
2Productivity
If the number of acquired views is reduced to decrease scan time, then scan time is reduced, but image resolution and signal-to-noise ratio deteriorate
Solution Approach 1:
The invention changes the parameter of view sharing by reconstructing a composite image that combines information from multiple projection views, then using this composite image to constrain the backprojection of individual frames. This parameter change allows undersampled frames to be reconstructed with improved resolution and SNR compared to conventional independent reconstruction.
3Loss of time
If conventional backprojection is used with undersampled views, then scan time is reduced, but streak artifacts are produced in the reconstructed image
Solution Approach 1:
The composite image serves as an intermediary that mediates between the undersampled projection views and the final image reconstruction. By using the composite image's signal contour information to weight the backprojection distribution, the invention eliminates streak artifacts that would otherwise be produced by conventional backprojection of undersampled views.
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
Two-dimensional or three-dimensional, time-resolved MR frame images are acquired during a dynamic study of a subject. A composite MR image is produced and this is used to reconstruct each image frame by weighting the backprojection of each projection view acquired for that image frame (constrained backprojection). The composite image may be reconstructed from views acquired separately, or it may be produced by combining views acquired during the course of the dynamic study. A number of different clinical applications of the method are described.