Open Access Publications

The Institute's work is published in both traditional journals (e.g. the prestigious imaging journal IEEE Transactions on Medical Imaging) and open access journals. For traditional journals, a preprint is uploaded to ArXiv whenever possible to make the research results freely available.

In addition, Tobias Knopp, as Editor-in-Chief, has founded a new scientific Open Access journal, which makes all articles available under the Creative Commons License (CC-BY-4.0). The International Journal on MagneticParticle Imaging (IJMPI) was founded in 2015 and publishes new research developments within the MPI community.

Open Access Publications

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Title: Simultaneous imaging of widely differing particle concentrations in MPI: problem statement and algorithmic proposal for improvement.
Written by: M. Boberg, N. Gdaniec, P. Szwargulski, F. Werner, M. Möddel, and T. Knopp
in: <em>Physics in Medicine & Biology</em>. April (2021).
Volume: <strong>66</strong>. Number: (9),
on pages: 095004
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DOI: 10.1088/1361-6560/abf202
URL: https://arxiv.org/abs/2205.01364
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Note: article, artifact, openaccess

Abstract: Magnetic Particle Imaging (MPI) is a tomographic imaging technique for determining the spatial distribution of superparamagnetic nanoparticles. Current MPI systems are capable of imaging iron masses over a wide dynamic range of more than four orders of magnitude. In theory, this range could be further increased using adaptive amplifiers, which prevent signal clipping. While this applies to a single sample, the dynamic range is severely limited if several samples with different concentrations or strongly inhomogeneous particle distributions are considered. One scenario that occurs quite frequently in pre-clinical applications is that a highly concentrated tracer bolus in the vascular system shadows nearby organs with lower effective tracer concentrations. The root cause of the problem is the ill-posedness of the MPI imaging operator, which requires regularization for stable reconstruction. In this work, we introduce a simple two-step algorithm that increases the dynamic range by a factor of four. Furthermore, the algorithm enables spatially adaptive regularization, i.e. highly concentrated signals can be reconstructed with maximum spatial resolution, while low concentrated signals are strongly regularized to prevent noise amplification.