Multi-Patch Sequences in Magnetic Particle Imaging

In this project we develop multi-patch imaging sequences and reconstruction algorithms for enlarged measuring fields in magnetic particle imaging (MPI). The regular field-of-view (FOV) in MPI is limited due to physiological constraints such as tissue heating and nerve stimulation. In practice typical FOV are in the range of 2x2x1 cm³. In order to scan larger regions it is possible to shift the FOV to different positions and scan various smaller FOV, which can later be combined to a joint 3D dataset. Especially the reconstruction of multi-patch data is a computationally intensive and memory demanding task. In this project we develop algorithms for efficient reconstruction of multi-patch MPI data.

To reduce calibration time and speed up image reconstruction, we have introduced a number of different methods, including reducing the number of system matricessystem matrix warping, and overscan extrapolation.

Sketch of a multi-patch imaging sequence.

Publications

[185592]
Title: Reducing displacement artifacts in multi-patch magnetic particle imaging.
Written by: M. Boberg, T. Knopp, and M. Möddel
in: <em>10th International Congress on Industrial and Applied Mathematics (ICIAM 2023)</em>. (2023).
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on pages: 05026
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URL: https://iciam2023.org/registered_data?id=00283#05026
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Note: inproceedings, multi-patch, artifact

Abstract: Magnetic particle imaging determines the spatial distribution of superparamagnetic nanoparticles within a small field-of-view. Multi-patch approaches can expand the field-of-view at the cost of artifacts caused by field imperfections. Time-consuming calibration scans can reduce these displacement artifacts by measuring system matrices for each patch. In this contribution, only one central system matrix is used, which is warped according to the underlying magnetic fields, resulting in low calibration times and higher image quality.