PRINCE-CS MRI Reconstruction Using KLT and Intermediate Estimates

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Solution Overview

Problem

Current MRI technologies face a trade-off between image quality and scan time, with under-sampled k-space data leading to reduced signal-to-noise ratio and image degradation, requiring extensive computational time and memory usage for enhanced image reconstruction.

Innovation Solution

The PRINCE-CS method employs a prior-enhanced compressed sensing approach using a Karhunen-Loeve transform and element-wise multiplication to iteratively minimize artifacts in dynamic 2D-radial cardiac MRI, reducing computational time and memory usage while maintaining high temporal resolution and image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If k-space data is under-sampled to reduce scan time, then scan time is reduced, but image quality degrades with reduced signal-to-noise ratio and artifacts

Engineering Contradiction:
Improvescan timeVSAvoidimage quality
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The method performs a preliminary reconstruction to generate an initial estimate image before the final iterative reconstruction. This preliminary action provides a starting point that guides the subsequent refinement process, enabling faster convergence to a high-quality solution from under-sampled data.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention introduces an intermediate estimate image as a mediator between the under-sampled k-space data and the final reconstructed image. This intermediate representation contains preliminary structural information that facilitates the recovery of high-quality images from insufficient samples.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If conventional iterative reconstruction methods are used to enhance image quality from under-sampled data, then image quality improves, but computational time and memory usage increase

Engineering Contradiction:
Improveimage qualityVSAvoidcomputational efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

By performing a preliminary reconstruction to generate an initial estimate before the main iterative process, the method provides a informed starting point that significantly reduces the number of iterations required for convergence, thereby decreasing computational time and memory usage while maintaining image quality.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method uses the preliminary estimate image as feedback to guide the iterative reconstruction process. The estimate provides structural information that directs the optimization algorithm, enabling faster convergence and reducing the computational burden of achieving high-quality reconstructions from under-sampled data.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS8675942B2Prior enhanced compressed sensing (PRINCE-CS) reconstruction for dynamic 2D-radial cardiac MRI
Publication Date: 2014.03.18 SIEMENS HEALTHINEERS AG
  • US8675942B2 patent drawing
  • US8675942B2 patent drawing
  • US8675942B2 patent drawing

AI summary

A reconstructed image is rendered from a set of MRI data by first estimating an image with an area which does not contain artifacts or has an artifact with a relative small magnitude. Corresponding data elements in the estimated image and a trial image are processed, for instance by multiplication, to generate an intermediate data set. The intermediate data set is transformed and minimized iteratively to generate a reconstructed image that is free or substantially free of artifacts. In one embodiment a Karhunen-Loeve Transform (KLT) is used. A sparsifying transformation may be applied to generate the reconstructed image. The sparsifying transformation may be also not be applied.