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

[92916]
Title: Enlarging the field of view in magnetic particle imaging using a moving table approach.
Written by: P. Szwargulski, N. Gdaniec, M. Graeser, M. Möddel, F. Griese, T. Knopp
in: <em>Proceedings of SPIE Medical Imaging</em>. (2018).
Volume: <strong>10578</strong>. Number:
on pages: 10578 - 10578 - 7
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1117/12.2293602
URL: https://doi.org/10.1117/12.2293602
ARXIVID:
PMID:

[www]

Note: inproceedings, multi-patch

Abstract: Magnetic Particle Imaging (MPI) is a highly sensitive imaging modality, which allows the visualization of magnetic tracer materials with a temporal resolution of more than 40 volumes per second. In MPI the size of the field of view scales with the strength of the applied magnetic fields. In clinical applications this strength is limited by peripheral nerve stimulation and specific absorption rates. Therefore, the size of the field of view is usually no larger than a few cubic centimeters. To bypass this limitation additional focus fields and/or a external object movements can be applied. In this work we investigate the later approach, where an object is moved through the scanner bore one step at a time, while the MPI scanner continuously acquires data from its static field of view. Using 3D phantom and 3D+t in-vivo data it is shown that the data can be jointly reconstructed after reordering the data with respect to the stepwise object shifts and heart beat phases.