2022/03/11 by Sebastian Flassbeck, Flassbeck, Sebastian, Jakob Assländer +1 · 1 citation
Medicine · Physics and Astronomy · #Advanced MRI Techniques and Applications #FOS: Physical sciences #Medical Imaging Techniques and Applications #Medical Physics (physics.med-ph) #NMR spectroscopy and applications
paper · pdf · doi:10.48550/arxiv.2203.06099
openalex publication_date 2022/03/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Purpose: To minimize eddy current artifacts in periodic pulse sequences with\nbalanced gradient moments as, e.g., used for quantitative MRI.\n Theory and Methods: Eddy current artifacts in balanced sequences result from\nlarge jumps in k-space. In quantitative MRI, one often samples some spin\ndynamics repeatedly while acquiring different parts of k-space. We swap\nindividual k-space lines between different repetitions in order to minimize\njumps in temporal succession without changing the overall trajectory. This\nreordering can be formulated as a traveling salesman problem and we tackle the\ndiscrete optimization with a simulated annealing algorithm.\n Results: Compared to the default ordering, we observe a substantial reduction\nof artifacts in the reconstructed images and the derived quantitative parameter\nmaps. Comparing two variants of our algorithm, one that resembles the pairing\napproach originally proposed by Bieri et al., and one that minimizes all\nk-space jumps equally, we observe slightly lower artifact levels in the latter.\n Conclusion: The proposed reordering scheme effectively reduces eddy current\nartifacts in sequences with balanced gradient moments. In contrast to previous\napproaches, we capitalize on the periodicity of the sampled signal dynamics,\nenabling both efficient k-space sampling and minimizing artifacts caused by\neddy currents.\n