Accelerated PROPELLER MRI via Partial K-Space Sampling
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Solution Overview
Problem
Current MR imaging techniques, such as PROPELLER, face limitations in acquiring and reconstructing full blades of k-space data due to complexity, leading to increased scan time and motion-related artifacts.
Innovation Solution
A system and method that utilize a modified PROPELLER acquisition protocol, involving a plurality of gradient coils and RF coils, to acquire partially filled k-space blades, apply 1D Fourier Transform, and fill the remainder using reconstruction weights, while applying T2 decay correction to reduce artifacts and enhance image reconstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full blades of k-space data are acquired using conventional PROPELLER imaging, then motion artifact reduction is achieved, but scan time increases and device complexity increases
Solution Approach 1:
The patent applies partial action by acquiring only a portion of the k-space blade data rather than the full blade. Specifically, only the central region of k-space is sampled during each rotation, and the remaining peripheral regions are inferred through parallel imaging reconstruction algorithms. This partial sampling approach reduces scan time while maintaining sufficient data for motion-corrected image reconstruction.
Solution Approach 2:
The patent segments the k-space acquisition into multiple independent rotational passes, where each pass acquires data from a different angular orientation. By dividing the complete k-space coverage into sequential rotational segments and using parallel imaging to fill gaps, the system achieves full k-space coverage without requiring continuous long-duration scanning, thereby reducing motion artifacts and scan time.
2Measurement precision
If full blades of k-space data are acquired using conventional PROPELLER imaging, then complete k-space coverage is achieved, but device complexity increases
Solution Approach 1:
The patent introduces parallel imaging reconstruction algorithms as an intermediary process that bridges the gap between partial k-space sampling and complete image reconstruction. These algorithms use coil sensitivity information and spatial encoding to infer missing k-space data from the partially sampled central region, eliminating the need for complex hardware modifications while achieving complete k-space coverage through computational methods.
Solution Approach 2:
The patent changes the sampling parameters by acquiring data at multiple rotational angles with partial k-space coverage at each angle. By varying the angular parameter and using parallel imaging with appropriate reconstruction weights, the system achieves complete k-space coverage through multiple parameter variations rather than requiring full sampling at each angle, thereby reducing overall system complexity.
3Loss of time
If partial blades of k-space data are acquired to reduce scan time, then scan time decreases, but image quality and diagnostic precision deteriorate
Solution Approach 1:
The patent implements feedback through iterative parallel imaging reconstruction that uses coil sensitivity profiles and spatial encoding information to refine the estimation of missing k-space data. The reconstruction algorithm continuously adjusts reconstruction weights based on the acquired partial data and inferred data, providing feedback that improves image quality and diagnostic precision even with reduced scan time.
Solution Approach 2:
The patent performs preliminary acquisition of the central k-space region, which contains the most critical low-frequency information for image quality. By prioritizing sampling of this central region and using parallel imaging to infer peripheral high-frequency details, the system ensures that essential image quality parameters are maintained while reducing overall scan time through selective preliminary sampling.
Data Source
AI summary
A system and method of MR imaging enables PROPELLER imaging to be feasibly carried out independently of slice orientation or anatomy of interest. The invention is directed to accelerated acquisition of blades of MR data that are rotated about a central region of k-space and reconstructing an image of arbitrary slice orientation from the blades of MR data that preserves contrast and reduces acceleration artifacts caused by signal amplitude variances.